Charles Spurgeon Commentary Exodus 15:24-27

"And the people murmured against Moses, saying, What shall we drink? An he cried unto 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; and he said, If thou wilt diligently hearken to the voice of Jehovah thy God, and wilt do that which is right in his eyes, and wilt give ear to his commandments, and keep all his statutes, I will put none of the diseases upon thee, which I have put upon the Egyptians: for I am Jehovah that healeth thee. And they came to Elim, where were twelve springs of water, and threescore and ten palm-trees: and they encamped there by the waters." — Exodus 15:24-27 (ASV)

Against Moses, saying, What shall we drink? And he cried unto the LORD; and the LORD shewed him a tree, which when he had cast into the waters, the waters were made sweet: there he made for them a statute and an ordinance, and there he proved them, and said, If thou wilt diligently hearken to the voice of the LORD thy God, and wilt do that which is right in his sight, and wilt give ear to his commandments, and keep all his statutes, I will put none of these diseases upon thee, which I have brought upon the Egyptians: for I am the LORD that healeth thee. And they came to Elim,

They did not stop long at Marah, probably only a few hours.