Sunan an-Nasa'i 2215

أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا جَرِيرٌ، عَنِ الأَعْمَشِ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَا مِنْ حَسَنَةٍ عَمِلَهَا ابْنُ آدَمَ إِلاَّ كُتِبَ لَهُ عَشْرُ حَسَنَاتٍ إِلَى سَبْعِمِائَةِ ضِعْفٍ قَالَ اللَّهُ عَزَّ وَجَلَّ إِلاَّ الصِّيَامَ فَإِنَّهُ لِي وَأَنَا أَجْزِي بِهِ يَدَعُ شَهْوَتَهُ وَطَعَامَهُ مِنْ أَجْلِي الصِّيَامُ جُنَّةٌ لِلصَّائِمِ فَرْحَتَانِ فَرْحَةٌ عِنْدَ فِطْرِهِ وَفَرْحَةٌ عِنْدَ لِقَاءِ رَبِّهِ وَلَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ ‏"‏ ‏.‏

It was narrated from Abu Hurairah that the Messenger of Allah said:"There is no good deed that the son of Adam does, but between ten and seven hundred Hasanahs will be recorded for him. Allah, the mighty and sublime, said: 'Except fasing, for it is for me and I shall reward for it. He gives up his desires and his food for my sake. Fasting is a shield, and the fasting person has two moments of joy. One when he breaks his fast and another when he meets his Lord. And the smell that comes from the mouth of the fasting person is better before Allah than the fragrance of musk

Reference

Sunan an-Nasa'i 2215

In-book

Book 22, Hadith 126