‏النكاح : Hadeeth No:3237 Sa'd b. Abi Waqqas (Allaah be pleased with him) reported: The Messengger of Allaah (sallAllaahu alayhi wa sallam) rejected (the idea) of Uthman b. Muz'unliving in celibacy (saying): And if he (the Prophet) had given me permission We would have got ourselves castrated....

‏فضائل الصحابة‏ : Hadeeth No:5982 This hadith has been narrated on the authority of Hisham with the same chain of transmitters with a slight variation of wording....