Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "Allah said: All the deeds of the son of Adam are for himself except for fasting, as it is, indeed, for Me, and I give reward for it. Fasting is a shield. When it is the day when any of you is fasting, let him not engage in obscenity and not speak in a loud voice. If anyone insults him or fights with him, let him say: Verily, I am a fasting person. By the One in Whose Hand the soul of Muhammad is, the smell of the mouth of the fasting person is more pleasant in the sight of Allah than the smell of musk. The fasting person will rejoice twice: when he breaks his fast, he rejoices, and when he meets his Lord, he rejoices at his fast." [Bukhari & Muslim] [authentic]