The water having followed them through all their former journeys, began now to fail them here, because they were now come near Canaan and other countries, where waters might be had by ordinary means, and therefore God would not use extraordinary, lest he should seem to prostitute the honour of miracles. This story, though like that Exo 17, is different from it, as appears by divers circumstances.
Related Commentaries of Numbers 20:2
Numbers 20:2
2 And there was no water for the congregation: and they gathered themselves together against Moses and against Aaron.