Sunan an-Nasa'i, Volume 3, Book 23, Hadith 2612 (DarusSalam) ⓘ
It was narrated from Anas bin Malik that the Messenger of Allah said: "The son of the daughter of a people is one of them."
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا وَكِيعٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " ابْنُ أُخْتِ الْقَوْمِ مِنْهُمْ " .
also referenced under: Hadith 2611 (Reference) & Book 23, Hadith 0 (In-Book)