Musannaf Ibn Abi Shaybah

Hazrat Abdul Malik bin Abi Sulaiman (may Allah have mercy on him) says that I asked Hazrat Ata (may Allah have mercy on him): Was there anyone among the companions (may Allah be pleased with them) of the Messenger of Allah (peace and blessings be upon him) who was more knowledgeable than Hazrat Ali (may Allah be pleased with him)? He (may Allah have mercy on him) replied: No, by Allah! I do not know anyone.