(Read Joshua 3:7-13)

The waters of Jordan shall be cut off. This must be done in such a way as never was done, but in the dividing of the Red sea. That miracle is here repeated; God has the same power to finish the salvation of his people, as to begin it; the WORD of the Lord was as truly with Joshua as with Moses. God’s appearances for his people ought to encourage faith and hope. God’s work is perfect, he will keep his people. Jordan’s flood cannot keep out Israel, Canaan’s force cannot turn them out again.

For a more detailed summary select the link below.

Joshua 3 Bible Commentary – Matthew Henry (concise) (christianity.com)

Joshua 3:7

⁷ Yahweh said to Joshua, “Today I will begin to magnify you in the sight of all Israel, that they may know that as I was with Moses, so I will be with you.