सहीह मुस्लिम #2637

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.'