Maliks Muwatta Book 005, Hadith Number 002.

Section : Doing Ghusl on the Day of Jumua.

Yahya related to me from Malik from Said ibn Abi Said al-Maqburi that Abu Hurayra used to say, "Doing ghusl as prescribed for major ritual impurity is incumbent (wajib) on the day of jumua on every male who has reached puberty."