[Machine] The Messenger of Allah ﷺ was asked by a man, "O Messenger of Allah, what is faith?" He replied, "When your good deeds make you happy and your bad deeds make you feel sad, then you are a believer." The man then asked, "O Messenger of Allah, what is sin?" He replied, "When something disturbs your heart, leave it." And this is how it has been narrated by Ali ibn Al-Mubarak and Ma'mar ibn Rashid through Yahya ibn Abi Kathir, following their conditions.
أَنَّ رَسُولَ اللَّهِ ﷺ سَأَلَهُ رَجُلٌ فَقَالَ يَا رَسُولَ اللَّهِ مَا الْإِيمَانُ؟ قَالَ «إِذَا سَرَّتْكَ حَسَنَتُكَ وَسَاءَتْكَ سَيِّئَتُكَ فَأَنْتَ مُؤْمِنٌ» فَقَالَ يَا رَسُولَ اللَّهِ مَا الْإِثْمُ؟ قَالَ «إِذَا حَاكَ فِي صَدْرِكَ شَيْءٌ فَدَعْهُ» وَهَكَذَا رَوَاهُ عَلِيُّ بْنُ الْمُبَارَكِ وَمَعْمَرُ بْنُ رَاشِدٍ عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍتابعه معمر وعلي بن المبارك وهو على شرطهما