Yazid bin al-Asamm (may Allah have mercy on him) said: Maymunah bint al-Harith (may Allah be pleased with her) informed me that the Messenger of Allah (peace and blessings be upon him) married her while he (peace and blessings be upon him) was not in ihram. And he said: She was my maternal aunt and the maternal aunt of Ibn Abbas (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9159