Musnad Abu Ya'la al-Mawsili 117:204

Abu Yasir narrated to us, Yusuf bin Atiyyah narrated to us, Thabit narrated from Anas that the Prophet, peace and blessings of Allah be upon him, said: "The creation is the dependents of Allah, and the most beloved of His creation to Him is the one who is most beneficial to His dependents."