The second intellectual reason for such infallibility is that...
The second intellectual reason for such infallibility is that, rather than advertising the content of revelation and their mission to the people, the prophets are responsible for educating and purifying and helping the most talented of people reach the highest level of man’s perfection. In other words, rather than teaching (ta’līm) and showing the people the right way, the prophets are responsible for educating (tarbiyah) and leading them.
Such an education is valuable and solely applies to the most talented and outstanding members of the society. To educate such people needs the most deserving educators who are themselves at the topmost level of man’s perfection and have the most perfect form of faculty (malakah) - the faculty of Infallibility (malakat al-‘ismah).
In addition, the educator’s behaviour in educating others is generally more important than his words; therefore, if a person has deficiencies in his behaviour, his words will not affect the people in a desirable way. Hence, God’s objective for sending prophets as the educators of people will not be thoroughly fulfilled unless they are immune against any kind of deviations in their words and behaviour.
Traditional reasons for the infallibility of prophets (a) The Holy Qur’an has described a group of people as being, “purified for the sake of God” (mukhlas), (the word mukhlas is different from mukhlis.
The former refers to a person who has been purified by God, and the latter is a person who is pure in performing his worship).Satan does not intend to mislead this group of people, who are exempted from his oath to mislead the children of Adam (a): “He (Iblīs) said, ‘By Your might, I will surely pervert them, except Your exclusive servants among them” (Sād:82-83).
There is no doubt that Satan’s refusal to mislead them is due to their immunity against being misled or corrupted; otherwise his enmity would include them and he would do whatever was in his power to seduce them. Thus, the term used to describe being purified for the sake of God is synonymous with being infallible (ma’sūm). Although there is no evidence for the allocation of infallibility being given to the prophets (as), it is certainly one of their qualities.
The Holy Qur’an refers to some of the prophets as being purified for the sake of God (mukhlasīn). For instance: “And remember Our servants Abraham, Isaac and Jacob, men of strength and insight.