Sahih Bukhari Volume 004, Book 052, Hadith Number 283.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 52. Fighting for the Cause of Allah (Jihaad)
Narated By Abu Juhaifa : I asked Ali, "Do you have the knowledge of any Divine Inspiration besides what is in Allah's Book?" 'Ali replied, "No, by Him Who splits the grain of corn and creates the soul. I don't think we have such knowledge, but we have the ability of understanding which Allah may endow a person with, so that he may understand the Qur'an, and we have what is written in this paper as well." I asked, "What is written in this paper?" He replied, "(The regulations of) blood-money, the freeing of captives, and the judgment that no Muslim should be killed for killing an infidel."