عَنْ عُبَادَةَ بْنِ الصَّامِتِ رَضِيَ اللَّهُ عَنْهُ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «مَنْ شَهِدَ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ حَرَّمَ الله عَلَيْهِ النَّار»

Abu Umama reported that a man asked God’s messenger what faith was, to which he replied, “When your good deed pleases you and your evil deed grieves you, you are a believer.” He then asked what sin was and received the reply, “When you have a besetting sin, give it up.” Ahmad transmitted it.