MSTC(i)
23 At the last they came to Marah: but they could not drink of the waters for bitterness, for they were bitter. Therefore the name of the place was called Marah.
24 Then the people murmured against Moses, saying, "What shall we drink?"
25 And Moses cried unto the LORD, and he showed him a tree: and he cast it into the water, and they waxed sweet. There he made them an ordinance and a law, and there he tempted them,