Hadith: Righteousness is good character, and sin is what wavers in your heart, and you dislike that people know about it

عَنِ النَّوَّاسِ بْنِ سِمْعَانَ رَضِيَ اللهُ عَنْهُ عَنِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ:
«البِرُّ: حُسْنُ الخُلُقِ، وَالإِثْمُ مَا حَاكَ فِي صَدْرِكَ، وَكَرِهْتَ أَنْ يَطَّلِعَ عَلَيْهِ النَّاسُ». وَعَنْ وَابِصَةَ بْنِ مَعْبَدٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: أَتَيْتُ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ فَقَالَ: «جِئْتَ تَسْأَلُ عَنِ البِرِّ وَالإِثْمِ»، قُلْتُ: نَعَمْ، قَالَ: «اسْتَفْتِ قَلْبَكَ، البِرُّ: مَا اطْمَأَنَّتْ إلَيْهِ النَّفْسُ، وَاطْمَأَنَّ إلَيْهِ القَلْبُ، وَالإِثْمُ: مَا حَاكَ فِي نَفْسِكَ وَتَرَدَّدَ فِي الصَّدْرِ، وَإِنْ أَفْتَاكَ النَّاسُ وَأَفْتَوْكَ».
[صحيح] - [الحديث الأول: رواه مسلم، والحديث الثاني: رواه أحمد والدارمي.] - [الأربعون النووية: 27]

An-Nawwās ibn Sim‘ān (may Allah be pleased with him) reported that the Prophet (ﷺ) said:
"Righteousness is good character, and sin is what wavers in your heart, and you dislike that people know about it."
[Authentic hadith] - [الحديث الأول: رواه مسلم، والحديث الثاني: رواه أحمد والدارمي] - [الأربعون النووية - 27]

Explanation

The Prophet (ﷺ) informed about righteousness and sin. He said: The most excellent among the traits of righteousness is good morals with Allah by piety and with people by enduring their harm, refraining from anger, having a cheerful face, speaking good words, upholding good ties and companionship, and being obedient and amiable. Righteousness is what the heart and soul feel at peace with. As for sin, it is whatever stirs uneasiness in the soul from suspicious matters, causing hesitation without the chest opening up to it, and what brings about doubt in the heart and fear that it may be a sin. It is also what you would not want to disclose, since it is ugly in the eyes of dignified and upright people. This is because the soul, by nature, loves for people to know of its good deeds; so if it dislikes people's knowing about some of its actions, then it is a sin and contains no good—even if people give you legal opinions regarding it. Do not rely on their fatwa so long as the sign of doubt lingers within you, for a fatwa does not remove true doubt if the mufti gives a ruling without knowledge. However, if the fatwa is based on sound evidence from the Shariah, then the questioner must follow it, even if his heart does not feel completely at ease with it.

Benefits from the Hadith

1. Encouraging the act of adopting noble morals because good morals are among the greatest aspects of righteousness.
2. The believer does not feel confused about the truth and falsehood; rather, he knows the truth through the light in his heart and turns away from falsehood and disapproves of it.
3. Anxiety and uneasiness of the heart along with disliking the idea of making it known to people are among the signs of sinfulness.
4. As-Sindi said: This applies to suspicious matters when people are not aware of the right choice. Otherwise, what is enjoined in the Shariah, without the existence of a relevant proof, falls under righteousness, and what is prohibited falls under sinfulness, and there is no need to refer to the heart and its tranquility in both cases.
5. The Hadīth addresses those who possess a sound natural disposition, not those with reversed hearts that do not recognize what is good or reject what is evil except what is engraved therein of their whims.
6. At-Tībi said: It was said that righteousness in the Hadīth was interpreted in various ways. He interpreted it in one position as what the soul and the heart feel at ease about. In another position, he interpreted it as faith, and in a different position as what brings you close to Allah, and here as good morals, and he defined good morals as the endurance of harm, the avoidance of anger, having a cheerful face, and speaking good words, which are all close in meaning.