Musnad Ahmad 25:535

Ya'qub narrated to us, he said: My father narrated to us, from Muhammad ibn Ishaq, he said: Aban ibn Salih and Abdullah ibn Abi Najih narrated to me, from Ata' ibn Abi Rabah and Mujahid Abu al-Hajjaj, from Ibn Abbas: "That the Messenger of Allah, peace and blessings of Allah be upon him, married Maymunah bint al-Harith while he was on a journey, and he was in a state of ihram."