It is narrated from Sayyiduna Abu Malik al-Ash'ari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Friday is an expiation for the sins between it and the Friday before it, with an addition of three days. That is because Allah, the Mighty and Majestic, said: 'Whoever comes with a good deed will have ten times the like of it' [Surah al-An'am: 160]."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3446