Sahih al-Bukhari 1904
Narrated Abu Huraira:
Allah's Messenger (ﷺ) said, "Allah said, 'All the deeds of Adam's sons (people) are for them, except fasting 
which is for Me, and I will give the reward for it.' Fasting is a shield or protection from the fire and 
from committing sins. If one of you is fasting, he should avoid sexual relation with his wife and 
quarreling, and if somebody should fight or quarrel with him, he should say, 'I am fasting.' By Him in 
Whose Hands my soul is' The unpleasant smell coming out from the mouth of a fasting person is 
better in the sight of Allah than the smell of musk. There are two pleasures for the fasting person, one 
at the time of breaking his fast, and the other at the time when he will meet his Lord; then he will be 
pleased because of his fasting."
حَدَّثَنَا إِبْرَاهِيمُ بْنُ مُوسَى، أَخْبَرَنَا هِشَامُ بْنُ يُوسُفَ، عَنِ ابْنِ جُرَيْجٍ، قَالَ أَخْبَرَنِي عَطَاءٌ، عَنْ أَبِي صَالِحٍ الزَّيَّاتِ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ ـ رضى الله عنه ـ يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ قَالَ اللَّهُ كُلُّ عَمَلِ ابْنِ آدَمَ لَهُ إِلاَّ الصِّيَامَ، فَإِنَّهُ لِي، وَأَنَا أَجْزِي بِهِ‏.‏ وَالصِّيَامُ جُنَّةٌ، وَإِذَا كَانَ يَوْمُ صَوْمِ أَحَدِكُمْ، فَلاَ يَرْفُثْ وَلاَ يَصْخَبْ، فَإِنْ سَابَّهُ أَحَدٌ، أَوْ قَاتَلَهُ فَلْيَقُلْ إِنِّي امْرُؤٌ صَائِمٌ‏.‏ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ، لِلصَّائِمِ فَرْحَتَانِ يَفْرَحُهُمَا إِذَا أَفْطَرَ فَرِحَ، وَإِذَا لَقِيَ رَبَّهُ فَرِحَ بِصَوْمِهِ ‏"‏‏.‏