Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates from the Messenger of Allah (peace and blessings be upon him) that the Messenger of Allah (peace and blessings be upon him) said: "The five prayers, and the interval from one Friday to the next, are an expiation for sins, as long as he keeps away from the major sins."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20758