The Book of Marriage (Kitab Al-Nikah)

Muslim :: Book 8 : Hadith 3237

Sa'd b. Abi Waqqas (Allah be pleased with him) reported: The Messengger of Allah (may peace be upon him) rejected (the idea) of Uthman b. Muz'unliving in celibacy (saying): And if he (the Holy Prophet) had given me permission We would have got ourselves castrated.