The Prophet ﷺ said, "The son of a people's sister is one of them," or, "is from among them."
عن النبي ﷺ قال: ابن أخت القوم منهم، أو من أنفسهم.
Bukhari narrated it in the Book of Inheritance (6762) from Abu Walid, who said, Shuba narrated to us, from Qatada, from Anas, and he related it.Muslim narrated it in the Book of Zakat (1059) through another route from Shuba with his chain, saying, the Messenger of Allah ﷺ gathered the Ansar and said, "Is there anyone among you who is not one of you?" They said, "No, except a nephew of ours." The Messenger of Allah ﷺ said, "The nephew of a people is one of them." Then he mentioned the virtues of the Ansar, and this is recorded in its proper place.