Q. I have always been told that Prophets/Messengers do not sin. According to the Islamic teaching. Is this true? And if it is what about Musa a.s. killing a man? And Adam a.s. and the forbidden tree? If it is possible for some reference to this question so I may research further would be very much appreciated.

A. It is the true and correct position that Allah's Prophets do not sin. It has been said that the acts mentioned in the question took place before sayyidina Adam and sayyidina Musa were granted prophethood, and Allah knows best. A reference for these questions would be Qadi `Iyad's book al-Shifa', available in English.