Abu Hurairah said:"The Messenger of Allah said: '(Allah says) Every deed of the son of Adam is for him, except fasting; it is for me and I shall reward for it. Fasting is a shield. If any one of you is fasting, let him no utter obscene talk or raise his voice in anger, and if anyone insults him or wants to fight, let him say: I am fasting. By the One in whose hand is the soul of Muhammad, the smell coming from the mouth of the fasting person is better before Allah than the fragrance of musk. The fasting person has two moments of joy: When he breaks his fast he rejoices at breaking his fast and when he meets his Lord, the Mighty and Sublime, he will rejoice at having fasted." '
أَخْبَرَنِي إِبْرَاهِيمُ بْنُ الْحَسَنِ، عَنْ حَجَّاجٍ، قَالَ قَالَ ابْنُ جُرَيْجٍ أَخْبَرَنِي عَطَاءٌ، عَنْ أَبِي صَالِحٍ الزَّيَّاتِ، أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " كُلُّ عَمَلِ ابْنِ آدَمَ لَهُ إِلاَّ الصِّيَامَ هُوَ لِي وَأَنَا أَجْزِي بِهِ وَالصِّيَامُ جُنَّةٌ إِذَا كَانَ يَوْمُ صِيَامِ أَحَدِكُمْ فَلاَ يَرْفُثْ وَلاَ يَصْخَبْ فَإِنْ شَاتَمَهُ أَحَدٌ أَوْ قَاتَلَهُ فَلْيَقُلْ إِنِّي صَائِمٌ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ يَوْمَ الْقِيَامَةِ مِنْ رِيحِ الْمِسْكِ لِلصَّائِمِ فَرْحَتَانِ يَفْرَحُهُمَا إِذَا أَفْطَرَ فَرِحَ بِفِطْرِهِ وَإِذَا لَقِيَ رَبَّهُ عَزَّ وَجَلَّ فَرِحَ بِصَوْمِهِ " .
Nesai
The Book of Fasting • Hadith 2216