مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1514
Musnad Abu Ishaq Sa'd bin Abi Waqqas
Saeed bin al-Musayyab narrated that he heard Sa"d bin Abi Waqqas say: ’Uthman bin Maz"oon wanted to be celibate, but the Messenger of Allah (ﷺ) told him not to. If he had allowed him to do that, we would have gotten ourselves castrated.
Musnad Ahmad 1514Sahih (Darussalam), al-Bukhari (5073) and Muslim (1402)]