On the authority of Abu Hurayrah (may Allah be pleased with him) from the Prophet (peace and blessings of Allah be upon him), who said:
"Allah (mighty and sublime be He) says:
'Fasting is Mine and it is I Who give reward for it. [A man] gives up his sexual passion, his food and his drink for My sake.' Fasting is like a shield, and he who fasts has two joys: a joy when he breaks his fast and a joy when he meets his Lord. The change in the breath of the mouth of him who fasts is better in Allah's estimation than the smell of musk."
[Bukhari (also by Muslim, Malik, at-Tirmidhi, an-Nasa'i and Ibn Majah).]
عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ، عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ:
" يَقُولُ اللَّهُ عَزَّ وَجَلَّ: الصَّوْمُ لِي، وَأَنَا أَجْزِي بِهِ، يَدَعُ شَهْوَتَهُ وَأَكْلَهُ وَشُرْبَهُ مِنْ أَجْلِي، وَالصَّوْمُ جُنَّةٌ(1)، وَلِلصَّائِمِ فَرْحَتَانِ: فَرْحَةٌ حِينَ يُفْطِرُ، وَفَرْحَةٌ حِينَ يَلْقَى رَبَّهُ، وَلَخُلُوفُ(2) فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ".