Musannaf Ibn Abi Shayba 17:1182

Waki’ narrated to us, from Sufyan, from Ibn Khuthaym, from Isma’il ibn ‘Ubayd Allah ibn Rifa’ah, from his father, from his grandfather, who said: The Messenger of Allah (may Allah bless him and grant him peace) gathered Quraysh and said: "Is there among you anyone who is not of you?" They said: "No, except for our sister’s son, our ally, and our freed slave." He said: "Your sister’s son is of you, and your ally is of you, and your freed slave is of you."