وَعَن النَّواس بن سمْعَان قَالَ: سَأَلَتْ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنِ الْبِرِّ وَالْإِثْمِ فَقَالَ: «الْبِرُّ حُسْنُ الْخُلُقِ وَالْإِثْمُ مَا حَاكَ فِي صَدْرِكَ وَكَرِهْتَ أَن يطلع عَلَيْهِ النَّاس» . رَوَاهُ مُسلم
Nawwas bin Sam'an (may Allah be pleased with him) reports: I asked the Messenger of Allah (peace and blessings be upon him and his family) about virtue and sin. He (peace be upon him) said: "Virtue is good character, while sin is that which troubles your heart and you dislike that people should come to know of it." Narrated by Muslim.