Musnad Ahmad 7:20

'Attab narrated to us, 'Abdullah narrated to us, he said: 'Abdullah ibn 'Uqbah—who is 'Abdullah ibn Lahi'ah ibn 'Uqbah—informed us, Yazid ibn Abi Habib narrated to me, from one who heard 'Abdullah ibn al-Mughirah ibn Abi Burdah saying: I heard Sufyan ibn Wahb al-Khawlani saying: When we conquered Egypt without a treaty, al-Zubayr ibn al-'Awwam stood up and said: "O 'Amr ibn al-'As, divide it." 'Amr said: "I will not divide it." Al-Zubayr said: "By Allah, you shall divide it just as the Messenger of Allah, peace and blessings of Allah be upon him, divided Khaybar." 'Amr said: "By Allah, I will not divide it until I write to the Commander of the Faithful." So he wrote to 'Umar, may Allah be pleased with him, and 'Umar wrote back to him: "Leave it as it is, so that the offspring of the offspring may fight from it."