Uthman bin Mazun wanted to devote himself entirely to worship and renounce marriage, but the Messenger of Allah ﷺ forbade him. Had he permitted it for him, we would have castrated ourselves.
حدثنا حجاج أنبأنا ليث حدثني عقيل عن ابن شهاب أخبرني سعيد بن المسيب أنه سمع
أراد عثمان بن مظعون أن يتبتل فنهاه رسول الله ﷺ ولو أجاز ذلك له لاختصينا
Its chain of transmission is sahih. Bukhari and Muslim, Tirmidhi, Nasai, and Ibn Majah also related it, as noted in Dhakhair 2064.Uthman bin Mazun was an early companion, one of the first to embrace Islam, becoming Muslim after only thirteen men had preceded him. He died after taking part in Badr, in the second year, and he was the first of the migrants to die in Madinah and the first of them to be buried in Baqi, may Allah have mercy on him and be pleased with him. When Ibrahim, the son of the Messenger of Allah ﷺ, died, he said, "Join our righteous predecessor, Uthman bin Mazun."