The son of Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) reports from his father that the Prophet (peace and blessings be upon him) said: "Remorse is repentance, and the one who repents from sin is like one who has no sin."
Al-Tabarani recorded it; its chain contains a narrator whom I do not know.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب التوبة / 17519
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (306/22) ، أخرجه شرح السنة برقم: 1307»