Musnad Abu Ya'la al-Mawsili 154:100

Mujahid ibn Musa narrated to us, Ishaq ibn Yusuf narrated to us, Sufyan informed us, from Muhammad ibn ‘Ajlan, from al-Qa‘qa‘ ibn Hakim, who said: ‘Abd al-‘Aziz ibn Marwan wrote to Ibn ‘Umar: "Submit your need to me." He said: So Ibn ‘Umar wrote back: "The Messenger of Allah (ﷺ) said: 'The upper hand is better than the lower hand, and begin with those whom you support.' And I do not ask you for anything, nor do I reject a provision that Allah has provided me through you."