Sunan an-Nasa'i, Hadith 4981 ⓘ
It was narrated that 'Atiyyah said: 'I was among the prisoners of Quraizah; we were examined, and whoever had grown (pubic) hair was killed, and whoever had not grown hair, he was allowed to live and was not killed."
أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ عَبْدِ الْمَلِكِ بْنِ عُمَيْرٍ، عَنْ عَطِيَّةَ، أَنَّهُ أَخْبَرَهُ قَالَ كُنْتُ فِي سَبْىِ قُرَيْظَةَ وَكَانَ يُنْظَرُ فَمَنْ خَرَجَ شِعْرَتُهُ قُتِلَ وَمَنْ لَمْ تَخْرُجِ اسْتُحْيِيَ وَلَمْ يُقْتَلْ .
also referenced under: Book 46, Hadith 111 (In-Book) & Volume 5, Book 46, Hadith 4984 (DarusSalam)