حَدَّثَنَا إِبْرَاهِيمُ بْنُ الْمُنْذِرِ، قَالَ: حَدَّثَنَا مَعْنٌ، عَنْ مُعَاوِيَةَ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ جُبَيْرٍ، عَنْ أَبِيهِ، عَنْ نَوَّاسِ بْنِ سَمْعَانَ الأَنْصَارِيِّ
أَنَّهُ سَأَلَ رَسُولَ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنِ الْبِرِّ وَالإِثْمِ؟ قَالَ: الْبِرُّ حُسْنُ الْخُلُقِ، وَالإِثْمُ مَا حَكَّ فِي نَفْسِكَ وَكَرِهْتَ أَنْ يَطَّلِعَ عَلَيْهِ النَّاسُ
It is reported Nawwas ibn Saman asked the Messenger of Allah (sallallahu alayhi wa sallam), may Allah bless him and grant him peace, about righteousness and sin. He said, “Righteousness is good character and sin is what gnaws at your conscience and that which you dislike for other people to become aware of.”
Al-Adab Al-Mufrad 296, Book 14, Excellence in Character, Hadith 37. 1 min read