Sahih Bukhari
Companions of the Prophet
Volume: 005 / Book Number: 057 / Hadith Number: 107
Narrated Abu Musa Al-Ashari:
My brother and I came from Yemen, and for some time we continued to consider 'Abdullah bin Mas'ud as one of the members of the family of the Prophet because we used to see him and his mother going in the house of the Prophet very often.