Comentario sobre Exodo 14:22

הלכו ביבשה, seeing the deep parts under the sea had all become frozen from the east wind so that the Israelites were crossing on frozen mud.

בתוך הים ביבשה, in the midst of the sea on dry land. The words "in the midst of the sea" mean in the inner part of (what had formerly been) the sea; the word ביבשה means that the sea bed was not muddy but completely dry.

ויבאו בני ישראל בתוך הים, “the Children of Israel went into the midst of the sea;” the Israelites did not cross the sea by using it as a convenient crossing on their way to the land of Canaan, as it is well known that there is no sea separating Egypt from the land of Canaan. The only reason they had to enter the sea at all, was to give G-d a chance to lure the Egyptians to their death through pursuing the Israelites. This is why they turned back from the desert of Eytam to the sea.

והמים להם חומה, and the waters formed a wall for them, etc. This means that parts of the waters had not been blown aside by the wind. The words: "on their right and on their left" mean that those waters did not form an actual wall but merely that they surrounded the Israelites on either side.

בתוך הים, “into the midst of the sea;” even if they set half a foot inside the water this is already called: בתוך הים. We know this from Numbers 11,4 when the Torah in describing the riffraff amongst the Israelites, of whom surely there were only very few, as והאספסוף בתוך העם, “the riffraff in the midst of the people.” Surely they had been at the fringe of the people!