Then Moses led Israel from the Red Sea, and they went out into the wilderness of Shur; and they went three days in the wilderness and found no water.
When they came to Marah, they could not drink the waters of Marah, for they were bitter; therefore it was named Marah.
So the people grumbled at Moses, saying, "What shall we drink?"
Then he cried out to the LORD, and the LORD showed him a tree; and he threw [it] into the waters, and the waters became sweet. There He made for them a statute and regulation, and there He tested them.