Mishkat al-Masabih 1 Faith كتاب الإيمان 40

وَعَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: إِذَا أَحْسَنَ أَحَدُكُمْ إِسْلَامَهُ فَكُلُّ حَسَنَةٍ يَعْمَلُهَا تُكْتَبُ لَهُ بِعشر أَمْثَالهَا إِلَى سبع مائَة ضعف وكل سَيِّئَة يعملها تكْتب لَهُ بِمِثْلِهَا ”

Abu Huraira reported God’s messenger as saying, “When one of you makes a good profession of Islam, every good deed he does will be recorded for him ten to seven hundredfold, and every evil deed he does will be recorded as it is till he meets God.” (Bukhari and Muslim.)