The most important of all the sources of Islam is, undoubtedly, the Holy Qur'an; which is immediately followed by the practices of the Prophet. After Prophet Muhammad (e), if any one - no matter who that person may be - were to speak out on an essentially religious topic, it could be accepted as binding if, and only if, it is seen to be in consonance with the ruling of the Qur'an and the Prophetic traditions. The Qur'an has clearly stated that all the prophets had been exemplary personalities. Furthermore, there are extant numerous sayings of the Prophet which speak of the great purity of their lives. It is, however, true that biblical tales and the other legends of Israel have, indeed found a place of their own in the books authored by Muslim writers in later ages. True Muslims do not accept any of these as sources that are either relevant or authentic. In fact, Muslims believe that the messengers of God were all men of the most exemplary nature.