Yahya related to me from Malik from Nafi from Ibn Umar that theMessenger of Allah, may Allah bless him and grant him peace, said,"When you come to jumua, do ghusl."Malik said, "It is notenough for someone to do a ghusl on the day of jumua and intend by itthe ghusl for jumua unless he does the ghusl and then sets off. Thatis because the Messenger of Allah, may Allah bless him and grant himpeace, said in the hadith related by Ibn Umar, 'When you come tojumua, do ghusl .' "Malik said, "If someone does ghusl onthe day of jumua and intends by it the ghusl of the day of jumua andthen sets out, whether early or late, and does something which breakshis wudu, he only has to do wudu and his ghusl remains valid for him."
USC-MSA web (English) reference: Book 5, Hadith 5
Arabic reference: Book 5, Hadith 230