In the 71st verse of Chapter 17, the Qur'an says: (Remember) the day when We will call every people by their Imam; then whoever is given his book in his right hand, these shall read their book; and they shall not be dealt with a whit unjustly.
Exegetes have interpreted the word "Imam" in this verse in a variety of different ways. Some of them are as follows:
(1) Imam here means the scriptures that the people followed like the Torah, the Gospel and the Qur'an.
(2) For those who were on the right path, their Imam will be their prophet; and as for those who pursued falsehood, their Imam will be Satan and the leaders of misguidance.
(3) Imam means their records of deeds or the Guarded Tablet.
(4) Imam in this verse is the plural of umm (mother), so people will be called by the names of their mothers.
(5) Imam means any intelligible or unintelligible being that is followed and subscribed to, including leaders like prophets and saints, as well as false ones like Satan and chiefs of misguidance; true religions and false ones; divine scriptures and misleading books; righteous traditions and unrighteous ones.
The view of the author of al-Mizan:
"The day" in the verse is the Day of Resurrection and "Imam" is a leader who is followed by the people. The verse also applies to all of the people from the beginning to the end. In other words, the verse clearly implies that every group of people will have an Imam of its own that is different from the Imam of the other groups because of the pronoun "their" in the verse. It now becomes evident that the Imam of every people means the person who they followed in the path of either truth or falsehood. As a matter of fact the Qur'an calls both of such leaders "Imams".
Sometimes the Imam of guidance is a messenger as was the case with Abraham and Muhammad (peace be upon them) and sometimes he is not. Furthermore, the clause "their Imam" in the verse is mentioned in an absolute form. It means that it can apply to a rightful Imam assigned by God or the leaders of misguidance appointed by themselves or by the people. Therefore the Imam in the verse is a person that people took to as their leader in their lives and the role model that they followed in this world as opposed to someone that God chose for leadership and assigned to guide by His command, irrespective of the people following him or forsaking him.
By contemplating on the verse and the one following it, we can infer that what is meant by "calling" in the verse is that the people will be gathered and summoned with their respective leader (of guidance or misguidance) whom they followed. As for those who subscribed to a true leader they will be given their record of deeds in their right hands and the blindness of those who failed to recognize the true Imam of their time will manifest.
In summary, people on the day of Resurrection will be divided into two groups. One group, who followed the true Imam of their time, is given their record of deeds in their right hands, and they shall read their record with delight, pleasure and happiness and they shall be rewarded fully. The second group who did not recognize the true Imam of their time and did not follow the true path will not find salvation and felicity in the life hereafter and will not achieve forgiveness and mercy. The state of the second group is evident in the following verse which says: And whoever is blind in this, he shall (also) be blind in the hereafter, and more erring from the way (17:72) where the pronoun "this" implies "this world" and subsequently, the clause "being blind in this" means not recognizing the true Imam in "this world".
Reference: Al-Mizan, English Volume 25, pp. 224-229, first edition, Tawheed Institute Australia Ltd., 2015.