Mishkat al-Masabih 2374
Ibn ‘Abbas reported God’s messenger as saying, “God records the good deeds and the evil deeds. If anyone intends to do a good deed but does not do it, God enters it for him in His record as a complete good deed:
and if he intends to do a good deed and does it, God enters it for him in His record as ten to seven hundred and many more times as much. If anyone intends to do an evil deed and does not do it, God enters it for him in His record as a complete good deed; but if he intends to do it and does it, God records it for him as one evil deed.”

(Bukhari and Muslim.)
وَعَنِ ابْنِ عَبَّاسٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: 
" إِنَّ اللَّهَ كَتَبَ الحسناتِ والسيِّئاتِ: فَمَنْ هَمَّ بِحَسَنَةٍ فَلَمْ يَعْمَلْهَا كَتَبَهَا اللَّهُ لهُ عندَهُ حَسَنَة كَامِلَة فَإِن هم بعملها كَتَبَهَا اللَّهُ لَهُ عِنْدَهُ عَشْرَ حَسَنَاتٍ إِلَى سَبْعِمِائَةِ ضِعْفٍ إِلَى أَضْعَافٍ كَثِيرَةٍ وَمَنْ هَمَّ بسيئة فَلَمْ يَعْمَلْهَا كَتَبَهَا اللَّهُ عِنْدَهُ حَسَنَةً كَامِلَةً فَإِن هُوَ هم بعملها كتبهَا الله لَهُ سَيِّئَة وَاحِدَة "