Sayyiduna Jabir (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "The deeds are presented (before Allah Almighty) on Monday and Thursday. Whoever is seeking forgiveness, Allah Almighty forgives him; whoever is repenting, his repentance is accepted; and those who hold resentment against one another are left as they are until they repent."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 12967