Musnad Abu Ya'la al-Mawsili 117:96

Abu al-Rabi' narrated to us, Yusuf ibn 'Atiyyah narrated to us, from Thabit, from Anas, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Creation is the family of Allah, and the most beloved of them to Allah is the one who is most beneficial to His family."