It was narrated that Ash-Sha'bi said:
I heard Abu Juhaifah say: 'We asked 'Ali: Do you have anything from the Messenger of Allah apart from the Qur'an? He said: No, by the One who splits the seeds and creates the soul, unless Allah gives a slave understanding of His Book, or except this sheet. I said: What is in the sheet? He said: In it are (the regulations concerning) blood money and the freeing of captives and (the rule) that no Muslim should be killed for killing a disbeliever.