Dawud bin Abi Hind, Isma'il bin Abi Khalid and Zakariyya bin Abi Za'idah said: Six of the Companions of the Prophet (peace and blessings be upon him) collected the Qur'an, all of them from the Ansar: Ubayy bin Ka'b, Mu'adh bin Jabal, Zayd bin Thabit, Abu Zayd and Sa'd bin Ubayd (may Allah be pleased with them).
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5471