When I and my brother came from Yemen we used to consider Ibn Mas'ud and his mother amongst the members of the household. of Messenger of Allah ﷺ because of their visiting them frequently and staying there for long (periods of) time.
قَدِمْتُ أَنَا وَأَخِي مِنَ الْيَمَنِ فَكُنَّا حِينًا وَمَا نُرَى ابْنَ مَسْعُودٍ وَأُمَّهُ إِلاَّ مِنْ أَهْلِ بَيْتِ رَسُولِ اللَّهِ ﷺ مِنْ كَثْرَةِ دُخُولِهِمْ وَلُزُومِهِمْ لَهُ
My brother and I came from Yemen (to Medina) and remained for some time, thinking that Ibn Masud and his mother belonged to the family of the Prophet ﷺ because of their frequent entrance (upon the Prophet) and their being attached to him.
فَمَكَثْنَا حِينًا مَا نُرَى ابْنَ مَسْعُودٍ وَأُمَّهُ إِلاَّ مِنْ أَهْلِ الْبَيْتِ مِنْ كَثْرَةِ دُخُولِهِمْ وَلُزُومِهِمْ لَهُ
"My brother and I arrived from Yemen, and we did not see a period except that we thought 'Abdullah bin Mas'ud was a man from the people of the house of the Prophet ﷺ, due to what we would see of him entering, and his mother's entering, upon the Prophet ﷺ." (Using translation from Tirmidhī 3806)
أَنَّهُ سَمِعَ أَبَا مُوسَى يَقُولُ «قَدِمْتُ أَنَا وَأَخِي مِنَ الْيَمَنِ فَمَكَثْنَا حِينًا مَا نَرَى إِلَّا أَنَّ عَبْدَ اللَّهِ بْنَ مَسْعُودٍ رَجُلٌ مِنْ أَهْلِ بَيْتِ رَسُولِ اللَّهِ ﷺ مِمَّا نَرَى مِنْ دُخُولِهِ وَدُخُولِ أُمِّهِ عَلَيْهِ»
My brother and I came from Yemen (to Medina) and remained for some time, thinking that Ibn Masud and his mother belonged to the family of the Prophet ﷺ because of their frequent entrance (upon the Prophet) and their being attached to him. (Using translation from Bukhārī 4384)
«قَدِمْتُ أَنَا وَأَخِي مِنَ الْيَمَنْ عَلَى رَسُولَ اللهِ ﷺ فَمَكَثْنَا حِينًا وَمَا نَحْسُبُ ابْنَ مَسْعُودٍ وَأُمَّهُ إِلَّا مِنْ أَهْلِ بَيْتِ النَّبِيِّ ﷺ مِنْ كَثْرَةِ دُخُولِهِمْ وَلُزُومِهِمْ لَهُ»