As for his words in commentary on the Qur’an, there are many.

Ibn Sa°d narrated that cAli said, ‘By Allah, an ayah has not been revealed without me knowing about what it was revealed, where it was revealed, and about whom it was revealed. My Lord has given me a very intelligent heart and a true and articulate tongue.’ Ibn Sacd and others narrated that Abu’t-Tufayl said: cAli said, Ask me about the Book of Allah, because there is no ayah but that I know whether it was revealed at night or in daytime, on the plain or in the mountain.’ Ibn Abi Dawud narrated that Muhammad ibn Sirin said: When the Prophet, may Allah bless him and grant him peace, died, cAli was slow to pledge allegiance to Abu Bakr. Abu Bakr met him and said, ‘Do you dislike my (having the) authority?’ He said, ‘No, but I have sworn not to don my mantle, except for the prayer, until I have collected together the Qur’an.’ They claimed that he wrote it in the order of its revelation. Muhammad (ibn Sirin) thus said, ‘If that book were come across, there would be knowledge in it.’