Sunan an-Nasa'i, Volume 3, Book 24, Hadith 2842 (DarusSalam) ⓘ
It was narrated from Ibn Abbas: That the Messenger of Allah married Maimunah when they were both in Ihram.
أَخْبَرَنِي إِبْرَاهِيمُ بْنُ يُونُسَ بْنِ مُحَمَّدٍ، قَالَ حَدَّثَنَا أَبِي قَالَ، حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، عَنْ حُمَيْدٍ، عَنْ مُجَاهِدٍ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم تَزَوَّجَ مَيْمُونَةَ وَهُمَا مُحْرِمَانِ .
also referenced under: Hadith 2839 (Reference) & Book 24, Hadith 0 (In-Book)