It was narrated that 'Abdul-Malik bin `Umair said:
"I heard 'Atiyyah Al-Quradhi say: 'We were presented to the Messenger of Allah (ﷺ) on the Day of Quraidhah. Those whose pubic hair had grown were killed, and those whose pubic hair had not yet grown were let go. I was one of those whose pubic hair had not yet grown, so I was let go."
English reference: Vol. 3, Book 20, Hadith 2541
Arabic reference: Book 20, Hadith 2638