Sahih al-Bukhari 874
Sahih al-Bukhari · Book 10: Call to Prayers (Adhaan) · Women praying behind men
Narrated Anas:
حَدَّثَنَا أَبُو نُعَيْمٍ ، قَالَ حَدَّثَنَا ابْنُ عُيَيْنَةَ ، عَنْ إِسْحَاقَ ، عَنْ أَنَسٍ ، قَالَ صَلَّى النَّبِيُّ صلى الله عليه وسلم فِي بَيْتِ أُمِّ سُلَيْمٍ، فَقُمْتُ وَيَتِيمٌ خَلْفَهُ، وَأُمُّ سُلَيْمٍ خَلْفَنَا.
The Prophet (ﷺ) prayed in the house of Um Sulaim; and I, along with an orphan stood behind him while Um Sulaim (stood) behind us.