From Sahih Muslim (Hadith 6341):
Hammam said:I said to Anas b. Malik: Who collected the Qur'an during the lifetime of Allah's Messenger (ﷺ)? He said: Four (persons), all of them belonging to Ansir: Ubayy b. Ka'b, Mu'adh b. Jabal, Zaid b. Thabit and a person from the Ansar whose Kunya was Abu Zaid
Reference: Muslim 6341