Then Moses led Israel from the Red Sea, and they went out into the Desert of Shur. For three days they walked in the desert without finding water.
Three days without water in a dry wasteland, no light trial. They should have prayed; instead they attacked Moses and demanded he wring drink from God as if He were his servant. Unbelief is always proud, too stubborn to ask directly, so it commands through intermediaries.
AI summary
The people could hardly tear themselves from that triumphant shore, yet the pleasures of our way to Canaan must not delay us, though a wilderness lies ahead. God trains His people by want and disappointment in the creature, that they may turn to the Creator where true comfort alone is found.
AI summary
Commenting on Exodus 15:22-27
And when they came to Marah,.... A place in the wilderness, afterwards so called from the quality of the waters found here; wherefore this name is by anticipation: they could not drink of the waters of Marah, for they were bitter; and they must be very bitter for people in such circumstances, having been without water for three days, not to be able to drink...