Accepting a bribe for doing something lawful

It must however be made clear that though it is permitted to gift something for lawful acts or to save oneself from oppression, it is detestable to accept such gifts. Because these gifts bear a close resemblance to bribe. Also, the habit of bribing for lawful things may make a man habitual and he may be inclined to pay bribes for unlawful purposes too. One is prone to error. If a pious person refrains for Makrooh (detestable) bribe he will never be prone to the haraam bribe. The following tradition supports this fact.

"Those are they for whom Allah does not desire that He should purify their hearts; they shall have disgrace in this world, and they shall have a grievous chastisement in the hereafter. (They are) listeners of a lie, devourers of what is forbidden." 
(Surah Maidah 5:41-42)

Explaining this ayat, Amirul Momineen Ali (a.s.) says: 
"It is that person who fulfills the wish of his believing brother and accepts a gift in return."

Shaykh Ansari says in the book, Makasibul Aamaal: "There are many explanations of this tradition. One of it is that we must absolutely refrain from accepting gifts in return for favours done that we may never fall into the trap of accepting bribe."

Characteristics of those who eat haraam

A typical feature of earnings by haraam means the money and wealth so acquired. It is narrated from Imam Ja'far as-Sadiq (a.s.) that he said,
"The madness of (acquiring or constructing) buildings. Mud and water occupies the head of one who earns by unlawful means."
(Behaarul Anwaar)

It means that a person with unlawful earnings is constantly worried about his wealth and strives to convert it into fixed property so that it is not lost. The buildings of mud and water neither benefit the owner in the Hereafter nor do they provide peace in this world. Such a person spends every bit of his wealth for pieces of land. Finally, Allah orders the land to swallow all his wealth.

Unlawful gains are harmful both from the worldly point of view as there is no barakat in such gain and also from the spiritual point of view as these form obstacles in the acceptance of acts of worship.

The Holy Prophet (s.a.w.s.) says: 
"When a single morsel of haraam enters the stomach of a person and becomes a part of his body, the angels of the sky and the earth curse him." 
(Safinatul Behaar)

The Messenger of Allah has also said: 
"Acts of worship accompanied by the acquiring of haraam are like buildings that rest on (crumbling) sand." 
(Safinatul Behaar)

They lack a firm foundation and hence are of no use. Such buildings can never remain intact and are soon destroyed.

Invocations are not accepted

The noble Messenger of Allah (s.a.w.s.) has remarked,
"Prayers of the one who eats a single morsel of haraam are not accepted for forty nights nor are his invocations accepted for forty days. Every piece of flesh that grows by consuming haraam is most deserving of being burnt in hell-fire and even a single morsel consumed causes some growth of flesh." 
(Safinatul Behaar)

The Holy Prophet (s.a.w.s.) has also stated, 
"One who wishes to have his invocations accepted must keep aloof from haraam food and unlawful earnings." 
(Al Kafi)

A man asked the Holy Prophet (s.a.w.s.): 
"I wish for the acceptance of my deeds." The Prophet (s.a.w.s.) told him, 
"Keep your food purified from haraam and do not let any unlawful thing enter your stomach." 
(Al Kafi)

The Almighty Allah revealed to Janabe Isa Ibne Maryam (a.s.): 
"Inform the oppressors of Bani Israel that they must not call Me and invoke Me as long as they are involved in unlawful earnings. And if they call Me and invoke Me in this condition, I will curse them." 
(Al Kafi)

Hardening of the heart

Whatever man eats is like a seed sown in the earth. If the seed is good it will bear sweet fruits. If the seed is bitter and poisonous, so is the fruit that grows from it. If the food is good and lawful it has beneficial effects on the heart. It is purified from every blemish and impurity. The organs of this person perform good deeds, but if one consumes food obtained through unlawful means it causes the heart to harden. The symptoms are soon obvious. A hard hearted person is unaffected by any kind of preaching and remains absolutely impenitent. Such a man is not moved even when he sees clear injustice. No good can be expected from him. Not a trace of goodness is visible in his dark heart. He refuses to accept what is right and is immune to every kind of moral advice. The tragedy of Karbala is the perfect example of this phenomenon. These are the characteristics clearly pointed out by Imam Husain (a.s.) in his address to the troops of Ibne Saad: 
"You bellies are filled with unlawful (wealth). Now you will not accept the truth. Why don't you deal with justice? Why don't you listen to me?" 
(Nafasul Mahmoom)

In other words, when a person's heart becomes hard and darkness occupies it. 
During the rule of the Abbasid King Mahdi, there was a Qazi named Shareek bin Abdullah. He was an honest and upright Judge, till the time he was summoned by the king. The Abbaside King forced him to opt one from three things 
(1) Either he should accept the post of the Royal Qazi 
(2) He should become the teacher of the King's son 
(3) or he should dine with the king, at least once.

The Qazi thought that easiest of the three was to eat with the king once, so he agreed to dine with King Mahdi. The ruler ordered the royal chef to prepare the best of the dishes. When the Qazi had eaten the food, the cook remarked to his companions, "Now, Qazi Shareek will never achieve salvation."

The prediction came to be true. The haraam food affected the Qazi to the extent that he also accepted the other two conditions. He became the special Qazi of the King and the tutor of his children. It is said that Qazi Shareek used to be very strict and unflinching with the treasurers while obtaining his share from the royal treasury.

One day the treasurer protested, "You have not sold me grain that you act so ruthless in recovering its price." Qazi Shareek replied, "Yes, I have sold something more valuable! I have sold my religion."

One day a tray filled with delicious dishes was sent by Haroon al-Rasheed for Bahlool. Bahlool did not accept it. The servants of the king said, "It is not possible to reject the present of the Caliph." Bahlool, the wise, pointed towards the stray dogs and said, "Give it to the dogs."

The servants became angry and said, "You have insulted the royal gifts." Bahlool became silent then said, "Be quiet, if the dogs learn that this food is sent by the king, they will not touch it."