Sunan an-Nasa'i, Hadith 3272 ⓘ
It was narrated from Abu Ash-Sha'tha' that Ibn 'Abbas told him: "The Prophet married Maimunah when he was a Muhrim."
أَخْبَرَنَا مُحَمَّدُ بْنُ مَنْصُورٍ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ أَبِي الشَّعْثَاءِ، أَنَّ ابْنَ عَبَّاسٍ، أَخْبَرَهُ أَنَّ النَّبِيَّ صلى الله عليه وسلم تَزَوَّجَ مَيْمُونَةَ وَهُوَ مُحْرِمٌ .
also referenced under: Book 26, Hadith 77 (In-Book) & Volume 4, Book 26, Hadith 3274 (DarusSalam)