Exodus 15:22-26

MLV(i) 22 And Moses led Israel onward 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. 23 And when they came to Marah, they could not drink of the waters of Marah, because they were bitter. Therefore the name of it was called Marah.
24 And the people murmured against Moses, saying, What will we drink? 25 And he cried to Jehovah. And Jehovah showed him a tree and he cast it into the waters and the waters were made sweet. There he made for them a statute and an ordinance and there he proved them.
26 And he said, If you will diligently listen to the voice of Jehovah your God and will do what is right in his eyes and will listen to his commandments and keep all his statutes, I will put none of the diseases upon you, which I have put upon the Egyptians, because I am Jehovah who heals you.