Musnad Ahmad 25:634

Abdullah ibn Bakr and Muhammad ibn Ja'far narrated to us, they said: Sa'id ibn Abi 'Arubah narrated to us, from Ya'la ibn Hakim, from Ikrimah, from Ibn Abbas, that he saw no harm in a man getting married while he is in the state of ihram. He would say: "The Prophet of Allah, peace and blessings of Allah be upon him, married Maymunah bint al-Harith at a water [source] called Sarif while he was in the state of ihram. When the Prophet of Allah finished his pilgrimage, he approached, and when he was at that water, he consummated the marriage with her."