Abu Musa Ashari reported,

My brother and I came from Yemen and stayed for a while, during which we thought that Abdullah bin Masud was a member of the Prophet's ﷺ household, because of how often we saw him and his mother entering upon the Prophet ﷺ.

Azami 10266

Sahih

عن أبي موسى الأشعري يقول

قدمت أنا وأخي من اليمن فمكثنا حينا، ما نرى إلا أن عبد الله بن مسعود رجل من أهل بيت النبي ﷺ، لما نرى من دخوله ودخول أمه على النبي ﷺ.

الأعظمي 10266صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Virtues of the Companions and reports about them
Chapter
Virtues of individual Companions and their reports
Section
Virtues of Abdullah bin Masud
Numbering
Jami al-Kamil 10266 (2nd edition)
Azami 10266