Ibn Saʿd narrated (3/394) with a good chain from Ibn Shihāb: that ʿUthmān ibn Maẓʿūn wanted to castrate himself and wander the earth, so the Messenger of Allāh (ṣallá Allāhu ʿalayhi wa-sallam) said to him: "Do you not have in me a good example? For I go to women, eat meat, fast, and break my fast. The castration of my ummah is fasting, and whoever castrates or seeks castration is not of my ummah." Al-Ḥusayn al-Marwazī also narrated in "Zawāʾid al-Zuhd" (1106) through the route of ʿAbd al-Raḥmān ibn Ziyād ibn Anʿam from Saʿd ibn Masʿūd who said that ʿUthmān ibn Maẓʿūn... and he mentioned it similarly without saying: "and whoever castrates or seeks castration is not of my ummah." However, Ibn al-Mubārak himself narrated it in "al-Zuhd" (845) through the route of Rushdīn ibn Saʿd who said: Ibn Anʿam narrated it to me in a more complete form. ʿAbd al-Raḥmān ibn Anʿam is weak due to his poor memory, and similarly is Rushdīn. Then al-Marwazī (1107) and Aḥmad (3/378 and 382-383) narrated through the route of a man from Jābir ibn ʿAbd Allāh who said: A young man came to the Messenger of Allāh (ṣallá Allāhu ʿalayhi wa-sallam) and said: "Do you permit me to castrate myself?" He said: "Fast, and ask Allāh for His bounty." Its chain is authentic except for the man who was not named. In summary, the ḥadīth with all these routes is authentic, except for the mention of standing [in prayer], which is rejected. And Allāh knows best. It is supported by the agreed-upon ḥadīth from Ibn Masʿūd, raised [to the Prophet]: "O young men, whoever among you can afford marriage, let him marry, for it lowers the gaze and guards chastity. And whoever cannot, let him fast, for it will be a shield for him."