Al-Kāfi

Hadith 1495
regret
4ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ مُحَمَّدِ بْنِ سِنَانٍ عَنْ مُعَاوِيَةَ بْنِ عَمَّارٍ قَالَ سَمِعْتُ أَبَا عَبْدِ الله (عَلَيهِ السَّلام) يَقُولُ إِنَّهُ وَالله مَا خَرَجَ عَبْدٌ مِنْ ذَنْبٍ بِإِصْرَارٍ وَمَا خَرَجَ عَبْدٌ مِنْ ذَنْبٍ إِلا بِإِقْرَارٍ.
4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Muhammad ibn Sinan from Mu’awiyah ibn ‘ Ammar who has said the following: “I heard Abu ‘Abdillah (a.s.) saying, ‘By Allah a servant cannot get out of sin while persisting in it and a servant cannot get out of sin without confessing to it.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī