In explaining the sacred verse:
لَهُ مُعَقِّبَاتٌ مِنْ بَيْنِ يَدَيْهِ وَمِنْ خَلْفِهِ يَحْفَظُونَهُ مِنْ أَمْرِ اللَّهِ [1]
“For his sake there are angels following one another, before him and behind him, who guard him by Allah’s commandment,” Imam Ali(a.s) has stated: “The protector angels protect man under all conditions.
Regarding this we have heard that “The generous God has assigned angels to Protect man.”
Angels protect man against fairies, other human beings and beasts.
Ka’ab has said,”If God had not assigned angels to protect you, the fairies would not have left you alone in your eating, drinking or sleeping with your wives”
Once the generous Prophet of Islam was asked how many angels accompany a person each time. He answered: One is in your right who records your righteous deeds. This angel supervises the activities of the angel on your left. When you do a good deed, the angel on the right makes it ten times more,. If you do a bad action, the angel on your left will ask the angel on your right: Shall I record it? The angel would say: no, perhaps he will repent. If he asks three times, the angel would then say: Now record it. May God make us free from him. What a bad associate he is! How little he is afraid of God! How inconsiderate he is! The Almighty God has declared:
لَهُ مُعَقِّبَاتٌ مِنْ بَيْنِ يَدَيْهِ وَمِنْ خَلْفِهِ
“For man there are angels following one another before him and behind him”
And there is an angel who leads you: if you are humble in front of your God, He will raise your rank and if you show pride in front of Allah, he will crush you. There are two angels stationed at your lips who will help you with your prayers. There is an angel in your mouth. There is an angel in your eyes. Each day ten angels protect you and each night there are ten angels who take care of you. Thus, there are twenty angels, day and night, who support you.[2]
The great expert on narration, Allama Majlisi, says in the volume 59 of Bihar, on page 153:
If I am asked: what is the benefit of these angels for man? I would then offer the following answers:
(1) Satan deceives man by getting him involved in sins; however, the angels encourage him to do good work.
(2) Mujahid has said: There is no God’s servant who is not accompanied by an angel to protect him against fairies, other men, and the beast.
(3) It happens most of the time that something occurs to our heart for which we may not present any real cause; but later on, it becomes clear that it was advisable that the action took place or did not happen. The angels here play significant roles.
(4) When we know that there is an angel who records our activities, then we will avoid committing sins. This is like when we will not do mischief in front of an honorable man.
source : THE LAND OF THE LOVERS An Exposition on Imam Zainol Abedin’s Sahifeh Sajjadieh VOLUME 1 BY Shaykh Husayn Ansariyan Translated by Dr. M. Farrokhpey