The Book of Marriage
26/29. Chapter:
A Man Marrying Off His Young Daughter
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا عَبْثَرٌ، عَنْ مُطَرِّفٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ أَبِي عُبَيْدَةَ، قَالَ قَالَتْ عَائِشَةُ تَزَوَّجَنِي رَسُولُ اللَّهِ صلى الله عليه وسلم لِتِسْعِ سِنِينَ وَصَحِبْتُهُ تِسْعًا .
It was narrated that Abu 'Ubaidah said: "Aishah said: 'The Messenger of Allah married me when I was nine and I lived with him for nine years.'"
Reference : Sunan an-Nasa'i 3257In-book reference : Book 26, Hadith 62English translation : Vol. 4, Book 26, Hadith 3259