Sunan an-Nasa'i 4981

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 ‏.‏

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

Reference

Sunan an-Nasa'i 4981

In-book

Book 46, Hadith 111