Aswad (may Allah have mercy on him) says: I heard Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) say: My brother and I came from Yemen, and we stayed here for some time, and we considered Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) to be simply a member of the household of the Prophet (peace and blessings be upon him), because he and his mother frequently went in to the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20583