Bitter water made sweet at Marah
After three days without water, Israel found only bitter water at Marah; God showed Moses a tree that made it sweet, then led them to the springs of Elim.
Then he cried to Yahweh. Yahweh showed him a tree, and he threw it into the waters, and the waters were made sweet. There he made a statute and an ordinance for them, and there he tested them.
Exodus 15:25 (World English Bible)
Three days after singing of God's victory, the people were grumbling. God answered with a lesson: if they would listen to him, he would be “Yahweh who heals you” (15:26). Their next camp, Elim, had twelve springs and seventy palm trees.
Places
Dating notes
A few days after the Red Sea crossing (Ussher, 1491 BC).