Charles Ellicott Commentary Mark 9:41

"For whosoever shall give you a cup of water to drink, because ye are Christ`s, verily I say unto you, he shall in no wise lose his reward." — Mark 9:41 (ASV)

Whosoever shall give you a cup of water.—See Note on Matthew 10:42. The reproduction of the promise in so different a context is significant as an instance of our Lord’s method of teaching, reiterating words of blessing and of wisdom until they were engraved indelibly on the minds of those who heard them.