Sahih al-Bukhari 3896
Sahih al-Bukhari · Book 63: Merits of the Helpers in Madinah (Ansaar) · Marriage of the Prophet (saws) with ‘Aishah رضي الله عنها
Narrated Hisham's father:
حَدَّثَنِي عُبَيْدُ بْنُ إِسْمَاعِيلَ ، حَدَّثَنَا أَبُو أُسَامَةَ ، عَنْ هِشَامٍ ، عَنْ أَبِيهِ ، قَالَ تُوُفِّيَتْ خَدِيجَةُ قَبْلَ مَخْرَجِ النَّبِيِّ صلى الله عليه وسلم إِلَى الْمَدِينَةِ بِثَلاَثِ سِنِينَ، فَلَبِثَ سَنَتَيْنِ أَوْ قَرِيبًا مِنْ ذَلِكَ، وَنَكَحَ عَائِشَةَ وَهْىَ بِنْتُ سِتِّ سِنِينَ، ثُمَّ بَنَى بِهَا وَهْىَ بِنْتُ تِسْعِ سِنِينَ.
Khadija died three years before the Prophet (ﷺ) departed to Medina. He stayed there for two years or so and then he married `Aisha when she was a girl of six years of age, and he consumed that marriage when she was nine years old.