Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) narrates: A young man came to the Prophet (peace and blessings be upon him) and said: "O Messenger of Allah! Permit me to castrate myself!" He said: "Fast, and ask Allah Almighty for His bounty!"
Imam Ahmad recorded this narration from a man, from Sayyiduna Jabir (may Allah be pleased with him); the remaining narrators of this narration are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب النكاح / 7319