Al-Kāfi

Hadith 1518
repentance
13ـ عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ سَهْلِ بْنِ زِيَادٍ عَنْ جَعْفَرِ بْنِ مُحَمَّدٍ الأشْعَرِيِّ عَنِ ابْنِ الْقَدَّاحِ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ إِنَّ الله عَزَّ وَجَلَّ يَفْرَحُ بِتَوْبَةِ عَبْدِهِ الْمُؤْمِنِ إِذَا تَابَ كَمَا يَفْرَحُ أَحَدُكُمْ بِضَالَّتِهِ إِذَا وَجَدَهَا.
13. A number of our people have narrated from Sahl ibn Ziyad from Ja’far ibn Muhammad al-Ash’ari from ibn al-Qaddah from Abu ‘Abdillah (a.s.) who has said the following: “Abu ‘Abd Allah (a.s.) has said, ‘The repentance of a servant (of Allah) from sins pleases Allah, the Majestic, the Glorious, more than a person’s finding a dearly cherished thing that he has lost.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī