Muwatta Malik #1860
Hair
Yahya related to me from Malik from Nafi that Abdullah ibn Umar
disapproved of castration and said, "The completeness of the created
form is in the testicles."
About Muwatta Malik
This hadith is #1860 from Muwatta Malik, in the Book of Hair. Muwatta Malik contains 1,985 hadiths across 61 books.