Sahih Muslim Book 8, Hadith Number 3285.

Chapter: Mubrim (one who is in the state of Ihram) is forbidden to marry and the disapproval of giving the proposal (in this state).

Yazid b. al-Asamm reported: Maimuna daughter of al-Harith narrated to me that Allah’s Messenger (May peace be upon him) married her and he was not in the state of Ihram. And she (Maimuna) was my mother’s sister and that of Ibn ‘Abbas (Allah be pleased with them).