Abu Hurairah relates that Allah’s Messenger (peace and blessings of Allah be to him) said, “The reward of each good act may be ten to seven hundred times, but the reward of fasting is an exception as God says, ‘Fasting is for My sake and I will reward for it as much as I like.’ A fasting man gives up food and drink for His sake. He will have two great joys: one, at the time of breaking fast; and the other on meeting his Lord. Smell of the fasting person’s mouth is better than that of musk before God and fasting is a shield against evil. A fasting man should not indulge in obscene talk or noisy demonstrations or rioting. If anyone abuses him, he should excuse himself from retaliation, saying that he is fasting.”
(Bukhari, Muslim)
The hadīth brings into light the blessings of fasting in Ramadan. First, the reward of fasting is unlimited. Allah keeps the reward of fasting due to Himself. Second, after experiencing hunger and thirst, he enjoys the pleasure of quenching his thirst and hunger. And, the joy of meeting the Lord is much more. Third, the smell caused by empty bowels is more pleasing to Allah than the fragrance of musk, because one fasts to seek only the pleasure of Allah.
Fast is described as a shield as it provides inner urge and power to defend oneself against the assaults of Satan. If the spirit of fast is fully observed, it will become evident how fast becomes a shield against sins.