Here is an account of when Hagar (Abraham's wife's servant) encounters the angel of the LORD.
Here is where the angel of the LORD stops Abraham from sacrificing his son Isaac.
In these posts, the angel of the LORD is presented as being God. You can find other posts with further discussion about the angel of the Lord by typing 'angel of the LORD' into the search box in the upper right hand corner of the blog.
In our passage, the cloud pillar also moves from its position of leading the way into a protective rear guard. This cloud brought light to the advancing Israelites, and darkness to the Egyptian side, keeping a separation between the two parties all night long.
Meanwhile, Moses was stretching his hand out over the sea. God drove the sea back using a strong east wind, leaving a dry path for the Israelites to travel between the two walls of water. Notice that the text is careful to provide the detail that the waters were standing in a wall on their right hand and on their left. Know why that is significant? Water doesn't usually stand up by itself. If this were merely the result of a strong wind blowing the water out of their way, there wouldn't be one wall of water on the right, a dry space and then another wall of water on the left. There would be no dry place in between, and no walls to walk between, for gravity would cause all the water to blend together in whatever place it was being blown toward.
I also loved the observation one commentator made about the possibility some scoffers postulate that the journey through the sea was actually made only through a lake, and that the quantity of water being blown aside was only several feet deep. Then, the commentator joked, the real miracle would have been how Pharaoh's entire army had been drowned in just a few feet of water. [But I am getting ahead of the story.]
Instead, the text asserts that it is the LORD who is driving the sea back all night long so that the Israelites would have a dry path between two walls of water. This passage is a beautiful example of how the LORD is continuing to keep the covenant He made with the children of Israel.