Sunan an-Nasai Book 27, Hadith 3429

أَخْبَرَنَا الرَّبِيعُ بْنُ سُلَيْمَانَ، قَالَ حَدَّثَنَا أَسَدُ بْنُ مُوسَى، قَالَ حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، عَنْ أَبِي جَعْفَرٍ الْخَطْمِيِّ، عَنْ عُمَارَةَ بْنِ خُزَيْمَةَ، عَنْ كَثِيرِ بْنِ السَّائِبِ، قَالَ حَدَّثَنِي أَبْنَاءُ، قُرَيْظَةَ أَنَّهُمْ عُرِضُوا عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم يَوْمَ قُرَيْظَةَ فَمَنْ كَانَ مُحْتَلِمًا أَوْ نَبَتَتْ عَانَتُهُ قُتِلَ وَمَنْ لَمْ يَكُنْ مُحْتَلِمًا أَوْ لَمْ تَنْبُتْ عَانَتُهُ تُرِكَ ‏.‏

It was narrated that Kathir bin As-Sa'ib said:"The sons of Quraizah told me that they were presented to the Messenger of Allah on the Day of Quraizah, and whoever (among them) had reached puberty, or had grown pubic hair, was killed, and whoever had not reached puberty and had not grown pubic hair was left (alive)