Musnad Abu Ya'la al-Mawsili 3:191

Abu Khaythama narrated to us, Ibn 'Uyaynah narrated to us, from Mutarrif, from al-Sha'bi, Abu Juhayfah informed me: He said: I said to 'Ali, "Do you have anything from the Messenger of Allah, may Allah bless him and grant him peace, other than the Book of Allah?" He said, "No, by the One who split the grain and created the soul, we have nothing other than the Book of Allah, except that Allah may grant a man understanding in this Qur'an, and what is in this scroll." He said, "The intellect, the ransom of the captive, and that a Muslim shall not be killed for a disbeliever."