The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah)
Muslim :: Book 31 : Hadith 6029
Anas is reported to have said: Four persons collected the Qur'an during the lifetime of Allah's Messenger (may peace be upon him) and all of them were Ansar: Mu'adh b. Jabal, Ubayy b. Ka'b, Zaid b. Thabit, Abu Zaid. Qatada said: Anas, who was Abu Zaid? He said: He was one of my uncles.