Expositor's Bible Commentary 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)

This verse seems to go best with v.37, before John’s interruption. The giving of a cup of water is a very small act of hospitality. Yet if it is given to one who belongs to Christ, this act receives God’s approval because it is the same as giving it to Christ.