Sahih Bukhari
Virtues of the Quran
Volume: 006 / Book Number: 061 / Hadith Number: 521
Narrated Masriq:
'Abdullah bin 'Amr mentioned 'Abdullah bin Masud and said, "I shall ever love that man, for I heard the Prophet saying, 'Take (learn) the Qur'an from four: 'Abdullah bin Masud, Salim, Mu'adh and Ubai bin Ka'b.' "