The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1867
Abu-Huraira reported Allah's Apostle (may peace be upon him) as saying: He who took a bath and then came for Jumu'a prayer and then prayed what was fixed for him, then kept silence till the Imam finished the sermon, and then prayed along with him, his sins between that time and the next Friday would be forgiven, and even of three days wore.