عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((إِنَّ اللَّهَ عَزَّ وَجَلَّ جَعَلَ حَسَنَةَ ابْنِ آدَمَ بِعَشْرِ أَمْثَالِهَا إِلَى سَبْعِمِائَةِ ضِعْفٍ إِلَّا الصَّوْمَ، وَالصَّوْمُ لِي وَأَنَا أَجْزِي بِهِ، وَلِلصَّائِمِ فَرْحَتَانِ، فَرْحَةٌ عِنْدَ إِفْطَارِهِ وَفَرْحَةٌ يَوْمَ الْقِيَامَةِ، وَلَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ))
It is narrated from Sayyiduna Abdullah bin Mas’ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: Allah Almighty has fixed the reward for every good deed of the son of Adam from ten to seven hundred times, except for fasting, for fasting is only for Me and I alone will give its reward. There are two joys for the fasting person: one joy at the time of breaking the fast, and the other on the Day of Resurrection. The smell from the mouth of the fasting person is purer to Allah Almighty than musk.