An-Nawawi Hadith - 37

إِنَّ اللهَ كَتَبَ الْحَسَنَاتِ وَالسَّيِّئَاتِ، ثُمَّ بَيَّنَ ذلِكَ: فَمَنْ هَمَّ بِحَسَنَةٍ فَلَمْ يَعْمَلْهَا كَتَبَهَا اللهُ عِنْدَهُ حَسَنَةً كَامِلَةً، وَإِنْ هَمَّ بِهَا فَعَمِلَهَا كَتَبَهَا اللهُ عِنْدَهُ عَشْرَ حَسَنَاتٍ إِلَى سَبْعُمِائَةِ ضِعْفٍ إِلَى أَضْعَافٍ كَثِيرَةٍ، وَإِنْ هَمَّ بِسَيِّئَةٍ فَلَمْ يَعْمَلْهَا كَتَبَهَا اللهُ عِنْدَهُ حَسَنَةً كَامِلَةً، وَإِنْ هَمَّ بِهَا فَعَمِلَهَا كَتَبَهَا اللهُ سَيِّئَةً وَاحِدَةً رَوَاهُ الْبُخَارِيُّ وَمُسْلِمٌ

Ibn Abbas, radiyallahu 'anhu, reported that the Messenger of Allah, sallallahu 'alayhi wasallam, related from his Lord (glorified and exalted be He): "Verily Allah has recorded the good deeds and the evil deeds." Then he clarified that: "Whosoever intends to do a good deed but does not do it, Allah records it with Himself as a complete good deed; but if he intends it and does it, Allah records it with Himself as ten good deeds, up to seven hundred times, or more than that. But if he intends to do an evil deed and does not do it, Allah records it with Himself as a complete good deed; but if he intends it and does it, Allah records it down as one single evil deed." [Al-Bukhari and Muslim]