From Sahih Muslim (Hadith 2708):
Abu Huraira and Abu Sa'id (Allah be pleased with both of them) reported Allah's Messenger (ﷺ) (as saying):Allah, the Exalted and Majestic, said: Fast (is exclusively) meant for Me and I would give its reward. There are two (occasions) of joy for the observer of fast. He feels joy when he breaks the fast and he is happy when he meets Allah. By Allah in Whose Hand is the life of Muhammad, the breath of the observer of fast is sweeter to Allah than the fragrance of musk
Reference: Muslim 2708