Sahih Muslim Book - 13, Hadith - 2706

وَحَدَّثَنِى مُحَمَّدُ بْنُ رَافِعٍ حَدَّثَنَا عَبْدُ الرَّزَّاقِ أَخْبَرَنَا ابْنُ جُرَيْجٍ أَخْبَرَنِى عَطَاءٌ عَنْ أَبِى صَالِحٍ الزَّيَّاتِ أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ - رضى الله عنه - يَقُولُ قَالَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- « قَالَ اللَّهُ عَزَّ وَجَلَّ كُلُّ عَمَلِ ابْنِ آدَمَ لَهُ إِلاَّ الصِّيَامَ فَإِنَّهُ لِى وَأَنَا أَجْزِى بِهِ وَالصِّيَامُ جُنَّةٌ فَإِذَا كَانَ يَوْمُ صَوْمِ أَحَدِكُمْ فَلاَ يَرْفُثْ يَوْمَئِذٍ وَلاَ يَسْخَبْ فَإِنْ سَابَّهُ أَحَدٌ أَوْ قَاتَلَهُ فَلْيَقُلْ إِنِّى امْرُؤٌ صَائِمٌ. وَالَّذِى نَفْسُ مُحَمَّدٍ بِيَدِهِ لَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ يَوْمَ الْقِيَامَةِ مِنْ رِيحِ الْمِسْكِ وَلِلصَّائِمِ فَرْحَتَانِ يَفْرَحُهُمَا إِذَا أَفْطَرَ فَرِحَ بِفِطْرِهِ وَإِذَا لَقِىَ رَبَّهُ فَرِحَ بِصَوْمِهِ ».

Abu Hurairah [may Allah be pleased with them] said: “The Messenger of Allah said: ‘Allah, the Most High, said: “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, so when it is a day when one of you is fasting, let him not utter any obscene speech that day nor raise his voice. If anyone reviles him, or argues with him, let him say: “I am a man who is fasting, I am fasting.” By the One in Whose Hand is the soul of Muhammad! The smell of the mouth of the fasting person will be better to Allah on the Day of Resurrection than the fragrance of musk. The fasting person has two moments of joy that he rejoices in: When he breaks his fast he rejoices at breaking his fast, and when he meets his Lord he will rejoice in his fasting.’”