Musnad Ahmad 31:25

Muhammad ibn Fudayl narrated to us, Dirar—meaning Ibn Murrah Abu Sinan—narrated to us, from Abu Salih, from Abu Hurayrah and Abu Sa’id, they said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, Allah the Almighty and Majestic says: 'Indeed, fasting is for Me, and I reward for it.'" "Indeed, for the fasting person there are two joys: when he breaks his fast, he rejoices, and when he meets Allah and He rewards him, he rejoices. And by the One in Whose hand is the soul of Muhammad, the change in the breath of the fasting person is more pleasant to Allah than the scent of musk."