Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Allah Almighty says: Fasting is for Me and I Myself will reward it, for he leaves his desire, his food and his drink for My sake. Fasting is a shield, and the fasting person has two joys: one joy at the time of breaking his fast and one joy at the time of meeting his Lord. And the smell of his mouth is more beloved to Allah Almighty than the fragrance of musk."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8109