Hatred of a people invite you not to act equitably

The following verse of Surah Maidah states:
"O you who believe! Be upright for Allah, bearers of witness with justice, and let not hatred of a people invite you not to act equitably; act equitably, that is nearer to piety, and be careful of (your duty to) Allah; surely Allah is aware of what you do." 
(Surah Maidah 5:8)

According to this ayat testimony should be given only to seek the pleasure of Allah. No feeling of enmity should be allowed to come in the way of stating the truth. Allah (a.j.) says in another verse:
"...and give upright testimony for Allah." 
(Surah Talaq 65:2)

Those who conceal evidence

Imam Muhammad al-Baqir (a.s.) remarks, 
"On the Day of Qiyamat, Allah shall cut off the flesh of one who conceals evidence; then order him to eat it before all the creatures." 
(Wasaelush Shia)

Imam Muhammad al-Baqir (a.s.) also says that those who conceal evidence are described in the Quran as those whose hearts have sinned. 'Hearts have sinned' actually implied that 'hearts have disbelieved'," according to Imam (a.s.)

Another tradition recorded from Imam (a.s.) is thus: 
"One who goes back upon his testimony or conceals it wholly, Allah shall cut off his flesh and force him to eat it before everyone. And when he will enter Hell he would be chewing at his own tongue." 
(Wasaelush Shia)

Hazrat Imam Musa al-Kazim (a.s.) says, 
"When you are asked to give evidence, give it. For Allah (a.j.) says: 
"Surely Allah commands you to make over trusts to their owners..." 
(Surah Nisa 4:58)

Evidence is itself a trust. Allah (a.j.) also says, 
"And who is more unjust than he who conceals a testimony that he has from Allah?" 
(Surah Baqarah 2:140) (Wasaelush Shia)

The following tradition of Amirul Momineen Ali (a.s.) is recorded in Tafseer Ali Ibn Ibrahim Qummi: 
"One who possesses some evidence, has to make it known. And when he is asked for it, he must give it. He should not fear anyone's criticism. He must fulfill his obligation of Amr bil Maroof (enjoining good) and Nahi Anil Munkar (forbidding evil)."

Is it wajib to testify?

Is it wajib to become a witness if one is requested to do so by a believer brother, in order he may achieve some benefit from the case he is pursuing in an Islamic Court? According to most of the Mujtahids it is wajib. Allah the Almighty Himself says:
".,.and call in to witness from among your men two witnesses; but if there are not two men, then one man and two women from among those whom you choose to be witnesses, so that if one of the two errs, the second of the two may remind the other; and the witnesses should not refuse when they are summoned." 
(Surah Baqarah 2:282)

Hisham says that Imam Ja'far as-Sadiq (a.s.) said, 
"And the witnesses should not refuse when they are summoned."
(Surah Baqarah 2:282)

And in the succeeding ayat, 
"...and do not conceal testimony", meaning concealing testimony from a Shariat judge."

Numerous traditions state that to be a witness is wajib (obligatory). For example, Muhammad Bin Fuzail asked Imam Musa al-Kazim (a.s.) the meaning of the above ayat (Surah Baqarah 2:282)

"And the witnesses should not refuse when they are summoned."

Imam (a.s.) replied, 
"When someone calls you to give evidence in a matter of some debts or some right, then you do not have the choice to ignore it." 
(Wasaelush Shia)

Of course the Quranic command in the verse 282 of Surah Baqarah asking the witness to testify before the Shariat judge implies that the person had in the first instance been a witness to the transaction etc.

The person who has witnessed the transaction etc. has to exercise extreme care and caution in this regard. He must memorise all the details or put them in writing, if necessary, so that there is no scope for doubt or misunderstanding in future. If this person is called upon to be a witness, it is wajib on him to comply, even if he has to roam some distance.

People whose supplications are not accepted

Hazrat Imam Ja'far as-Sadiq (a.s.) says: 
"Dua of four types of people is not answered: 
1. A Person who sits idle at home and prays to Allah to provide him with sustenance is told, 'Have We not ordered you to make effort for obtaining your sustenance?'

2. The person who prays for some misfortune for his wife. He is told, 'Have We not given you the choice of giving her divorce if you do not want such a wife?'

3. One who had squandered the money and spent it in evil ways. Now if he prays for sustenance, he is told, 'Did We not order you to spend in moderation?'

4. One who gives a loan to someone but does not make anyone witness it. Hence if the borrower refuses and the creditor prays, he is informed, 'Had We not ordered you to have witnesses?'"
(Iddatud Dai)

Testifying is wajib and concealing evidence, haraam

There may be occasion when a person has not directly witnessed a transaction but has some information for having heard or seen something related to the issue. If the information he has can save a Muslim from harm or enable him to secure his right, it is wajib on this person to testify if he is summoned. If he is not summoned, it is wajib for him to volunteer to testify byapproaching the Shariat judge with the information he has. If by not disclosing what he knows, a Muslim is harmed or loses his right, it is haraam to remain silent.

In short if a person is capable of helping the oppressed or prevent the oppressor from oppressing, it is wajib on him to do so.

It is not wajib to give evidence in a situation where not testifying does not cause any harm to a Muslim, nor does it deprive him of his right. In this case a person can even refuse to testify even if he is ordered to do so, because neither is he a direct witness to the dispute nor is his silence harmful in anyway.

Muhammad Ibne Muslim says, quoting an authentic tradition from Imam Muhammad al-Baqir (a.s.): "If one hears an evidence (i.e. he becomes a witness) but he had not been made a witness, then if he likes he can testify or he can prefer to remain silent." 
(Wasaelush Shia)

Testify only if you are certain

The witness is required to pay attention to all the aspects of the matter that he has witnessed and when he is testifying, he must only say that, about which he is certain. He must not mention those things, which he himself has not heard, or seen. It should be clear as the Sun, as mentioned in tradition.

When a true testimony will oppress someone

It should be known that a testimony should not endanger the life, property or honour of a Muslim. It should also not pose a threat to the life, property and honour of the witness. It is wajib to give evidence and haraam to conceal it so that justice is established in the society and injustice is eradicated. The oppressor ought to be punished and the right may be restored to its owner but if the testimony itself becomes the cause of oppression it is not wajib to testify. Rather it is haraam to do so and it is wajib to conceal evidence. For example if a person knows that if he testifies against a particular oppressor, the oppressor will take revenge on him or on his relatives or plunder his wealth, then it is wajib to conceal evidence. Similarly, there may be a situation where a debtor deep in debts is unable to clear his dues because of his poverty. At the same time he cannot prove his helplesness and the creditor is not prepared to spare him. In this case also it is wajib to conceal evidence, if the evidence given by a witness will cause the poor debtor to be oppressed.

The following traditions of our Masoomeen (a.s.) emphasise the justification of concealing evidence under special circumstances.

Hazrat Imam Musa al-Kazim (a.s.) says: 
"Give evidence for the sake of Allah even if you have to testify against yourself, your parents or your own relatives - But you must not cause harm to your believing brother by concealing evidence. However, if your believing brother is going to be oppressed, then do not testify." 
(Wasaelush Shia)

Dawood Ibne Hasan says that he heard Imam Ja'far as-Sadiq (a.s.) saying: 
"Give evidence for the sake of Allah, even if you have to testify against your parents or your own son. But do not give evidence to cause harm (Zaeer) to your believing brother."

The narrator says that, 'I asked, "What is Zaeer?" He (a.s.) said, 
"It is when someone who has a right, and in order to obtain it he resorts to oppression, contrary to the order of Allah and the Holy Prophet (s.a.w.s.). For example, a man is indebted to another, but the debtor is in straitened circumstances. In this situation, Allah has ordered that he must be given respite till he becomes self-sufficient. And (Allah) says, 
...then let there be postponement until (he is in) ease…

Now if in spite of this the creditor summons you to testify, and you know the poverty of the debtor, then it is not permitted for you to testify (that he has taken the loan)."
(Wasaelush Shia)

A Tradition from Imam Musa al-Kazim (a.s.)

Muhammad Ibne Qasim Ibne Fuzail narrates a tradition from Imam Musa al-Kazim (a.s.). He says, "I asked Imam (a.s.), 'One of your devotees has taken a loan from an enemy of yours. The creditor wants to oppress him and have him captive. Allah knows that he has no money to repay the debt, neither is he capable to do so at present. He does not even have Bayyanah (two just witnesses) to prove his bankruptcy. Then is it allowed for him to take an oath so that he can prove his bankruptcy and obtain respite till the return of favourable conditions? And if from your Shias there are some witnesses who can testify against him, (that he has taken the loan) can they testify?'"

Imam Musa al-Kazim (a.s.) replied, 
"It is not permitted for them to testify. And it is not permitted for the creditor to oppress the debtor." 
(Al Kafi)

When testifying harms

When we speak about haraam testimony that causes harm to a Muslim, we mean a wrongful harm or unjustified oppression but if the person deserves to be punished, it is wajib to give the evidence. For example a person commits a crime. The witness of this crime does not testify only because if he does so the one against whom he testifies will demand the debt which the witness owes him. This is not a valid excuse for withholding evidence. The criminal must be punished according to Shariat even if the witness has to suffer a monetary loss. However, if the hardship for the witness far outweighs the seriousness of the crime of the accused then the witness has a valid excuse to refrain from testifying.

Harm and being deprived of benefit

It must be mentioned that to be harmed is different from being deprived of some benefit. In the examples already mentioned, if a witness refrains from testifying due to fear that the accused will deprive him of some money, or that some benefit may not accrue to him; this does not amount to him being 'harmed'.

However if the accused is the employer of the witness and will fire him from his job thus causing untold hardship, then it is allowed for the witness to refrain from testifying as it could be regarded as 'harm' in common parlance.

Hence we can conclude that false oath, false testimony and concealing evidence, each of these are Greater sins if there is no risk of any harm. If there is any chance of any harm to a Muslim or an innocent witness, then they do not remain sins - they are permitted. Rather in some circumstances these actions become wajib as we have seen from the traditions of Masoomeen (a.s.). However as far as possible one must give priority to the more important alternative. 

The twenty-first of the Greater sins is 'Breaking of a promise.' There are authentic traditions to this effect from Abdul Azeem where he quotes that Imam Ja'far as-Sadiq (a.s.) has proved it to be a Greater sin with the help of the following verse of Holy Quran: 
"And those who break the covenant of Allah after its confirmation and cut asunder that which Allah has ordered to be joined and make mischief in the land; (as for) those, upon them shall be curse and they shall have the evil (issue) of the abode." 
(Surah Ra'd 13:25)

The Holy Quran denounces the breaking of promise in the following ayat too: 
"Yea, whoever fulfills his promise and guards (against evil) - then surely Allah loves those who guard (against evil).

(As for) those who take a slender price for the covenant of Allah and their own oaths - surely they shall have no portion in the hereafter, and Allah will not speak to them, nor will He look upon them on the Day of Resurrection nor will He purify them, and they shall have a painful chastisement." 
(Surah Ale-Imraan 3:76-77)

Similarly we find another verse of the same connotation: 
"Surely the vilest of animals in Allah's sight are those who disbelieve, then they would not believe.

Those with whom you make an agreement, then they break their agreement every time and they do not guard (against punishment)." 
(Surah Anfal 8:55-56)

This ayat is critical of the Jews of Bani Qurayza, who did not honour the pact, which they had formed with the Holy Prophet (s.a.w.s.) regarding cooperation with the infidels. They supplied arms to the disbelievers of Mecca for the Battle of Badr and thus invalidated the pact. Later they justified their action saying they had forgotten the pact.

They once more entered into a pact with the Holy Prophet (s.a.w.s.) only to violate it at the time of the Battle of Khandaq (trench). They went against the pact and sided with Abu Sufyan.

In various places in the Holy Quran we find that fulfilling a promise has been made obligatory and highly emphasised.

For example, 
"and fulfill the promise, surely (every) promise shall be questioned about." 
(Surah Bani Israel 17:34)

Also, 
"O you who believe! Fulfill the obligations." 
(Surah Maidah 5:1)

Similarly in Surah Baqarah the ayat says, 
"...and the performers of their promise when they make a promise..." 
(Surah Baqarah 2:177)

We also find the following verse: 
"O you who believe! Why do you say that which you do not do?

It is most hateful to Allah that you should say that which you do not do." 
(Surah Saff 61:2-3)

Imam Ja'far as-Sadiq (a.s.) has explained this ayat in the following manner: 
"A believer's promise to his believing brother is a vow that has no expiation (It cannot be broken). But one who goes back on his word declares his opposition and enmity to Allah, and invokes the anger of Allah." 
(Wasaelush Shia)

After this the Imam (a.s.) recited the above-mentioned ayat.

Amirul Momineen Ali (a.s.) advises Malik al-Ashtar regarding the honouring of promises: 
"Breaking a promise causes the anger of Allah." 
(Nahjul Balagha)

Ali (a.s.) also quotes the same verse after this. 
Hazrat Imam Muhammad al-Baqir (a.s.) said: 
"There are four types of sinners who are punished very soon:
a) The person who violates the pact that he has made with you, even though you have respected it. 
b) One who inflicts harm upon you even though you caused him no harm. 
c) One who has promised you something and you are faithful upon your agreement but he is unfaithful. 
d) One who wants to severe relations even though the relative wishes to continue the relationship."
(Khisaal)

Abu Malik inquired from Imam Zainul Abedin (a.s.), "Inform me about all the rules of religion." Imam (a.s.) told him, 
"To speak the truth, to judge with justice and to fulfill the promise." 
(Khisaal)

Although a vast number of traditions and ayats denounce the breaking of promises. We shall quote some selected ones.

Types of Promises

There are three types of promises:
1. Promise of Allah to His creatures. 
2. Promise of the creatures to Allah. 
3. Promises of the people among themselves.

The promise of Allah to His creatures is that of the Aalam-e-Zar (in the spiritual plane). We come to know of this promise through the Quranic ayats as well as the traditions. According to this, Allah first created the souls of all human beings and made the following covenant: That they remain upon the right path, do not associate anyone or anything with Allah, obey the commands of their Prophet, and do not follow Shaitan, Allah shall recompense them by helping them, by keeping them forever in His mercy, and give them a place in Paradise but if they do not respect their covenant, Allah will also disregard His side of the promise. It is for this very fact, that Allah says.

"...and be faithful to (your) covenant with Me, I will fulfill (My) covenant with you." 
(Surah Baqarah 2:40)

Allah also says, 
"Did I not charge you, O children of Adam, that you should not serve the Shaitan?" 
(Surah Yaseen 36:60)

The covenant that Allah took from the people in the spiritual plane also includes the oath with regard to the Wilayat (Mastership) of Amirul Momineen Ali (a.s.) and the Imams (a.s.). Numerous traditions mention this fact. It is even recorded in the various heavenly scriptures, and all the Prophets have conveyed the message of the Wilayat of the Fourteen Masoomeen (a.s.).

However, some scholars have rejected this concept of the Aalam-e-Arwah or Aalam-e-Zar. They give a different explanation to the traditions and ayats that deal with this subject. According to them Aalam-e-Arwah (the spiritual plane) is essentially the innate human nature, which is so designed by Allah (a.j.) that it is desirous of obeying Allah's command and does not desire to follow Shaitan. Of course the reasoning capacity of man directs him to follow his nature and accordingly obey Allahs orders. Hence if a man goes against Allah's command he goes against his own nature. These thinkers consider the covenant, to be the same as the innate nature given to us by Allah (a.j.). This book is not concerned with the detail of these two theories.

Anyway whether a man breaks the promise given in Aalam-e-Zar, or goes against his innate nature, he commits a greater sin. This fact has been emphasised in most ayats and traditions, and it is confirmed that honoring the covenant is wajib and not respecting it is haraam. It is also confirmed that the breaking of this first covenant can bring severe chastisement. The people are also warned of dire consequences in case of default. The traditions also inform us that serious retribution incured just for violating the first covenant, which is the greatest of the sins. Hence it is incumbent upon the people to fulfill their covenant so that Allah may also fulfill His promise.

Allah has promised to answer every prayer

One of the promises of Allah to His creatures is that He will answer every prayer, but this is only on condition that the supplicant honors this covenant with Allah (a.j.).

Jamil narrates from Imam Ja'far as-Sadiq (a.s.) who said, 
"When a man prays to Allah with a pure intention and a sincere heart, Allah answers (his prayer) after man has fulfilled his promise to Allah (a.j.). But if man prays to Allah without a pure intention and sincerity, Allah does not answer it. Has not Allah said, '...and be faithful to (your) covenant with Me, I will fulfill (My) covenant with you,' so the promise is kept only with one who keeps his own word.'
(Safinatul Behaar)

Verbal expression of a promise

The second type of promise is one that the man himself gives to Allah, like a vow or an oath. For an oath to be binding, it is necessary that it be expressed verbally. For example, if someone wants to vow to Allah and state it in Arabic language he should say 'Aahadto Allah' (I have vowed to Allah) or 'Alayya Ahadollah' (The vow for Allah is upon me). The statement of promise, oath or the vow can be in any language but expressed verbally. A vow for example may consist of saying, "if I return safe and sound from the journey, I shall give such and such amount as charity in the way of Allah."

If an oath is intended mentally and not expressed verbally, it is not binding.

Vow or oath for a useless thing

It must be remembered that a vow, oath or a promise should not be taken for a useless object. That is, the object must not be undesirable from the Islamic point of view. An oath taken to carry out some makrooh or haraam action, a vow to abstain from a wajib or a mustahab act is invalid. An oath taken for an action which is wajib and its avoidence haraam in a prevailing set of conditions, automatically becomes invalid if the conditions change. For example, a man vows to give a thousand rupees in charity if he gets well, but after he is well be becomes so poor that it is hardly possible for him to maintain his family. In these circumstances the vow is considered invalid and it is not wajib on him to fulfill it.

Vow should be for a useful aim

In conclusion it can be said that an oath should be taken if it is acceptable from the Shariat point of view. In any case an oath should be taken when common sense dictates that the oath serves some useful purpose, either by carrying out an action or by abstaining from it. For example to walk and exercise etc. which are beneficient and Mubah (permitted) actions, and to abstain from smoking which is harmful to health although Mubah.

Conditional and absolute covenant

Just as in the case of oath and vow, a covenant is also either conditional or absolute. An example of an absolute covenant is when a man says, "I make covenant with Allah that I shall perform such and such good action." Then this shall become binding upon him. If he does not do so he would have committed a Greater sin. In addition he also has to pay the penalty. The conditional covenant is the one when the person attaches some conditions. For example, he may say, "If Allah gives me a son, I will perform such and such good deed." Then that good deed becomes wajib upon him only when he gets a son. Once the condition is fulfilled it will also be haraam for him to leave the deed undone and he will have to pay the additional penalty also.

Three types of covenant with Allah

Actually a vow and an oath is also a covenant with Almighty Allah. Therefore a covenant is of three types. One is the covenant itself and of the other two one is a vow and the other an oath. It is only due to Divine Mercy that man is given a choice of three kinds of covenants in case he wishes to avoid the risk of being liable for keeping sixty fasts etc. Hence, he can make a vow or take an Islamic oath.

Expiation of a vow or a covenant

Breaking of a covenant, whether absolute or conditional, is haraam. The expiation becomes wajib in case of default. It is the same penalty as that of breaking or omitting, without any reason, a fast of the month of Ramazan, i.e. feeding sixty poor people, keeping sixty fasts or freeing a slave.

If a vow is broken its kaffarah (expiation) is same as that of breaking an oath. That is, feeding, or clothing ten poor people or freeing a slave; but if he cannot do any of these then it is wajib for him to keep three fasts.

Breaking of promise and hypocrisy

Breaking of a promise is a very serious sin. It is a sin that sows the seed of hypocrisy in the heart of the person who commits it. The person dies in a state of disbelief and is raised with the hypocrites on the Day of Judgment. The Holy Quran says: 
"And there are those of them who made a covenant with Allah: If He gives us out of His grace we will certainly give alms and we will certainly be of the good. But when He gave them out of His grace, they become niggardly of it and they turned back and they withdrew. So He made hypocrisy to follow as a consequence into their hearts till the day when they shall meet Him because they failed to perform towards Allah what they had promised Him and because they told lies." 
(Surah Tauba 9:75-77)

The Shaan-e-Nuzool (circumstances of Revelation) of this ayat, according to Tafseer Minhaj us-sadeqeen is as follows: "Thulbe Ibne Khatib was a very staunch and a prominent Christian. One day he came to the Holy Prophet (s.a.w.s.). He began to complain of his poverty, and requested the Holy Prophet (s.a.w.s.) to pray for him. The Holy prophet (s.a.w.s.) advised him, "Do not emphasise upon this prayer of yours but be patient in your circumstances. Too much of wealth is dangerous for you. If you are grateful for this favour it is better than too much of wealth that makes you unthankful. By Allah if I pray that mountains become gold and silver and move with me, Allah shall cause it to be so but I know that an honourable hereafter is better, and those who are well provided in this world have a difficult hereafter. So, follow the Prophet of Allah (a.j.) and accept his advice."

But Thulbe the Christian did not follow the advice of the Holy Prophet (s.a.w.s.) and again he came back to him with his entreaty and said: "O Prophet of Allah! I make a covenant to Allah that if He gives me abundant wealth I shall spend it upon the deserving ones and do good through it."

When he persisted in his request, the Holy Prophet (s.a.w.s.) prayed for the removal of his property.

Allah gave abundant increase in his livestock; and he became a Muslim. His animals multiplied and he became so busy in supervising them that he stopped praying behind the Holy Prophet (s.a.w.s.) in the congregational prayers. He prayed only the morning and the evening prayers. Then his herd became so bulky that the surrounding area of Madinah was not sufficient any more. He took his animals to the outskirts of the town and settled there. Now he was deprived of praying the daily prayers behind the Holy Prophet (s.a.w.s.). Still he continued to come to Madinah for the Friday prayers. Then his business expanded beyond the valleys surrounding Madinah. Finally he could not even attend the Friday prayers.

One day the Holy Prophet (s.a.w.s.) asked his companions, "Why is Thulbe not attending the congregation?" The people replied, "He has so many goats and sheep that a single valley is unable to accommodate them. Now he has moved to such and such valley and settled there. The Holy Prophet (s.a.w.s.) upon hearing this said, 
"Woe be upon Thulbe, Woe be upon Thulbe, Woe be upon Thulbe!"

Later when it was wajib to pay zakat due to the revelation of the verse of Zakat, the Holy Prophet (s.a.w.s.) summoned one of his followers and gave him this verse in writing and sent with him a tribesman of Bani Salim. The Prophet ordered, "After you have collected Zakat from Thulbe go to such and such good man and collect it from him too." Both of them went to Thulbe. They showed him the Quranic verse and also gave him the letter of the Holy Prophet (s.a.w.s.) containing the rules of Zakat. Thulbe had become so much attached to his wealth that he said, "Muhammad is collecting Jiziya from us! Go somewhere else! Meanwhile I shall think upon it."

The two men went to this righteous person (of the tribe of Bani Salim). When he saw the ayat and the letter of the Holy Prophet (s.a.w.s.), he said, "I hear and I obey the command of Allah and the Prophet (s.a.w.s.)."

He went among his camels and selected the best ones for Zakat and said, "Please take these for the Messenger of Allah (s.a.w.s.)." The agents told him that it was not wajib to give the best of the camels. He said, "How can I not offer the best for Allah and His Prophet (s.a.w.s.)?"

Then these two men came back to Thulbe. The wretched fellow repeated his previous objection and refused to pay Zakat.

When the Holy Prophet (s.a.w.s.) heard of this incident he said just once, "Woe be upon Thulbe!" Then the Holy Prophet (s.a.w.s.) prayed for the well being of the one who had paid the Zakat willingly.

The companions used to wonder why Thulbe had not accepted the advice of the Holy Prophet (s.a.w.s.) and saved himself from apostasy! (Zakat is one of the Dhururiyaat-e-Deen and one who says that Zakat is not wajib has apositisised and is no more a Muslim!) The ayats quoted before this discussion were revealed for Thulbe.

Mutual covenants and agreements

The third type of promise is when people form actual covenants and agreements. The ayats and the traditions state that it is wajib to fulfill this type of promise and it is haraam to go against them.

For example in Surah Bani Israel: 
"...and fulfill the promise; Surely (every) promise shall be questioned about." 
(Surah Bani Israel 17:34)

Similarly the Quran describes truthful and the pious people thus,
"...and those who fulfill their promise when they make a promise.." 
(Surah Baqarah 2:177)

Also when describing those who shall be saved from Hell and earn Paradise, Allah says, 
"And those who are keepers of their trusts and their covenant." 
(Surah Momin 23:8)

Imam Ja'far as-Sadiq (a.s.) says, 
"To keep your word to your believing brother is wajib like a vow, even though there is no expiation for going against it."

The Holy Prophet (s.a.w.s.) said: 
"One who has belief in Allah and in last day (Qiyamat) must keep his word when he promises." 
(Usool-e-Kafi)

Thus keeping a promise is a fulfillment for the belief in Allah and the Day of Qiyamat. Similarly, the beginning verses of Surah Saff have also denounced the breaking of promise and clearly prove that non-fulfillment of a promise (of every type) is haraam.

Hypocrites do not keep their words

The Holy Prophet (s.a.w.s.) is reported to have said: 
"Three traits make man a hypocrite even if he prays and fasts:
Betrayal of trust, lying and non-fulfillment of promise." 
(Usool-e-Kafi)

Imam Ja'far as-Sadiq (a.s.) says, 
"Those who are just in their dealing, those who do not lie and those who fulfill their promises are from those who have perfect morals. And it is haraam to criticise them behind their back. Their being just (Aadil) is obvious. To maintain brotherly relations with them is wajib." 
(Usool-e-Kafi)

It follows from this tradition, that a person who is unjust, a liar and one who does not keep his word, does not possess morals. He is not a just person (Aadil) but a transgressor (Fasiq) and it is not wajib to fulfill the rights of brotherhood towards him.

No concession

Imam Ja'far as-Sadiq (a.s.) has also remarked: 
"There are three obligations in fulfillment of which Allah does not give concession to any: To behave well with the parents, whether they are righteous or sinners; to fulfill ones promise; whether to a righteous person or a sinner; and to deliver a trust (to its owner) whether he is righteous or a sinner." 
(Shaykh Sadooq: Khisaal)

Amirul Momineen Ali (a.s.) says: 
"One must also fulfill that promise that he has made to his wife. For a Muslim is always wary of his promise except when it is for making a prohibited thing legal or prohibiting that which is permitted." 
(Tahzeeb)