Sayyiduna Atiyyah al-Qurazi (may Allah be pleased with him) said: I was among the captives of Banu Qurayzah. They would look, and whoever had grown pubic hair, they would kill him, and whoever had not grown it, they would leave him. I was among those whose hair had not yet grown.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحجر / 11315