Sufyan bin Wahb al-Khawlani said: When we conquered Egypt without a treaty, al-Zubayr bin al-Awwam (may Allah be pleased with him) stood up and said: O Amr bin al-As (may Allah be pleased with him), divide it. Amr (may Allah be pleased with him) said: I will not divide it. Al-Zubayr (may Allah be pleased with him) said: By Allah, you shall divide it, just as the Messenger of Allah (peace and blessings be upon him) divided Khaybar. Amr (may Allah be pleased with him) said: I will not divide it until I write to the Commander of the Believers. Umar bin al-Khattab (may Allah be pleased with him) wrote: Leave it as it is (undivided), so that the offspring of the offspring (generations to come) may campaign from it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الفيء والغنيمة / 12828