Sunan an-Nasa'i, Book 26, Hadith 79 (In-Book) ⓘ
It was narrated from Ibn 'Abbas that the Messenger of Allah married Maimunah when he was a Muhrim.
أَخْبَرَنَا أَحْمَدُ بْنُ نَصْرٍ، قَالَ حَدَّثَنَا عُبَيْدُ اللَّهِ، - وَهُوَ ابْنُ مُوسَى - عَنِ ابْنِ جُرَيْجٍ، عَنْ عَطَاءٍ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم تَزَوَّجَ مَيْمُونَةَ وَهُوَ مُحْرِمٌ .
also referenced under: Hadith 3274 (Reference) & Volume 4, Book 26, Hadith 3276 (DarusSalam)