Sunnah.com reference : Book 8, Hadith 31English translation : Book 8, Hadith 1001Arabic reference : Book 8, Hadith 994
Muslim reported from Maimunah (RA) herself:
"The Prophet (ﷺ) married her when he was not in the state of Ihram."
وَلِمُسْلِمٍ : عَنْ مَيْمُونَةَ نَفْسِهَا { أَنَّ اَلنَّبِيَّ ‏- صلى الله عليه وسلم ‏-تَزَوَّجَهَا وَهُوَ حَلَالٌ }   1‏ .‏‏1 ‏- صحيح .‏ رواه مسلم ( 1411 )‏.‏