(Due to the brevity of this lesson, it is reposted here in full; source.)
This is the second of the “Hallel Psalms” sung before the Passover meal. In Hebrew, this is the lyrical equivalent of a powerful appetizer — it is very small and simple, yet dense in satisfying flavor. These few brief words conjure up a savory memory of really big events.
It’s obvious this is about the Exodus, the founding miracle that defined just who Israel was, but more importantly, who God intended she be. The psalmist draws a strong connection here to explain how it works. Ancient Near Eastern feudalism was not about land, as with Western feudalism, but about the people. A ruler’s domain was his people. During that journey out of Egypt, a wholly alien people, Jehovah is depicted as personally present at the head of the march. He was Lord and Creator of all things, as He has just proved with the plagues that discredited all the claims of the Egyptian pantheon.
One thing Israel did have in common with Egypt was the fundamental assumption that Creation was alive. This is no mere figure of speech that sees the waters as pulling back to make room for the two crossings (Reed Sea and Jordan River). The water knew its Master and cooperated with His purpose.
Indeed, all of Creation wherever they passed was delighted to see the revelation of the Creator in His mighty acts. The mountains pranced like proud rams and playful sheep. Gladly did stone dissolve into water, for nothing was too great to ask in supporting and promoting this essential mission of God. He was raising up a nation to bear His message. Not merely the written record, but the living record of people precious in His sight who would claim the rich heritage of His blessings.