Sayyiduna al-Aswad bin Sari' (may Allah be pleased with him) says: A captive was brought to the Prophet (peace and blessings be upon him). He said: O Allah, I repent to You, and I do not repent to Muhammad (peace and blessings be upon him). Then the Prophet (peace and blessings be upon him) said: "He has recognised the right of the one to whom it belongs."
Ahmad and al-Tabarani recorded it; its chain contains Muhammad bin Mus'ab, whom Ahmad declared thiqah (trustworthy) while others declared him da'if (weak), and the rest of its narrators are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب التوبة / 17523