Sahih Muslim
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-Fadail Al-Sahabah)
Book Number: 031 / Hadith Number: 6024
Masruq reported: We used to go to Abdullah b. 'Amr and talk to him, Ibn Numair said: One day we made a mention of Abdullah b. Mas'ud, whereupon he said: You have made mention of a person whom I love more than anything else. I heard Allah's Messenger (may peace be upon him) as saying: Learn Qur'an from four persons: Ibn Umm 'Abd (i. e. 'Abdullah b. Mas'ud) he started from him-then Mu'adh b. Jabal and Ubayya b. Ka'b, then Salim the ally of Abu Hudhaifa.