Sahih Muslim #2637

Sahih (Authentic) Good Character
الْبِرُّ حُسْنُ الْخُلُقِ وَالإِثْمُ مَا حَاكَ فِي صَدْرِكَ وَكَرِهْتَ أَنْ يَطَّلِعَ عَلَيْهِ النَّاسُ

The Prophet (ﷺ) said: 'Righteousness is good character, and sin is that which wavers in your heart and which you do not want people to know about.'

— Sahih Muslim #2637

Sanad (Rantai Periwayatan)

Narrated An-Nawwas bin Sam'an