Abu Hurairah reported,

The Messenger of Allah ﷺ said, "Every deed of the son of Adam is multiplied, a good deed ten times over, up to seven hundred times, up to whatever Allah wills. Allah says, 'Except fasting, for it is Mine, and I Myself reward it. He gives up his food and drink for My sake.' The one who fasts has two moments of joy, a joy when he breaks his fast, and a joy when he meets his Lord. The smell of the fasting person's mouth is more pleasing to Allah than the fragrance of musk. Fasting is a shield, fasting is a shield."

حدثنا ابن نمير قال حدثنا الأعمش قال حدثنا أبو صالح قال قال أبو هريرة قال رسول الله ﷺ فذكر معناه