For whosoever shall give you to drink a cup of water in My name, because you belong to Christ: Amen I say to you, he shall not lose his reward. This is Christ"s further reason to show why the man must not be forbidden to cast out devils. It is as though Christ said, "If he who gives you a drink of water in My name, and for My sake, does well, and shall receive a reward from God, so likewise shall he who drives out devils in My name. For both the one and the other do a good work, and are profitable to their neighbours in regard and respect of Me. But the one confers so much the greater benefit than the other, by as much as the devil whom he drives out is more hurtful than the thirst which the other alleviates by a draught of water." So Theophylact.
