Psalms 106:9

He rebuked the Red sea also, and it was dried up
By sending a strong east wind, which drove the waters back, and made the sea a dry land, ( Exodus 14:21 ) .

So he led them through the depths;
that is, the deep waters of the sea, which were cast up as an heap, and stood as a wall on each side, through which they passed.

As through the wilderness;
or rather, "as on a plain"; for a passage through a wilderness where no roads are, and many obstructions be, is not easy; and so it is manifestly to be understood in ( Isaiah 63:13 ) , where Jarchi and Kimchi interpret it a plain and smooth ground, a champaign country; and so the word is used for a plain, in opposition to mountains, in ( Jeremiah 9:10 ) , and then the sense is, that God led them through the sea, being dried up, as if they were led through a plain and open country, where was nothing to obstruct their march; an emblem of baptism, ( 1 Corinthians 10:1 1 Corinthians 10:2 ) , and of the passage of the people of God through this world; (See Gill on Psalms 78:13).