Musannaf Ibn Abi Shayba 28:384

Yazid ibn Harun narrated to us, he said: Hisham informed us, from Ibn Sirin, from al-Ahnaf ibn Qays, who said: We were sitting at the door of Umar when a slave girl came out. We said, "Umar’s concubine." She said, "She is not a concubine for Umar. I am not lawful for Umar; I am from the wealth of Allah." So we discussed among ourselves what is lawful for him from the wealth of Allah. That reached him, so he sent for us and said, "What were you discussing?" We said, "A slave girl came out to us, and we said, 'This is Umar’s concubine.' She said, 'She is not Umar’s concubine; she is not lawful for Umar; she is from the wealth of Allah.' So we discussed among ourselves what is lawful for you from the wealth of Allah." He said, "I will inform you of what I deem lawful for myself from the wealth of Allah: the garment for winter and summer, what I perform Hajj and Umrah upon from the riding animal, and the sustenance of my family like a man from Quraysh—neither the wealthiest of them nor the poorest of them. I am a man among the Muslims; what befalls them befalls me."