What does Joshua 3:11 mean?

You shall command the priests who bear the ark of the covenant, saying, ‘When you come to the brink of the waters of the Jordan, you shall stand still in the Jordan.’”

Joshua said to the children of Israel, “Come here, and hear the words of Yahweh your God.”

Joshua said, “By this you shall know that the living God is among you, and that he will without fail drive the Canaanite, and the Hittite, and the Hivite, and the Perizzite, and the Girgashite, and the Amorite, and the Jebusite out from before you.

Now therefore take twelve men out of the tribes of Israel, for every tribe a man.

It shall be that when the soles of the feet of the priests who bear the ark of Yahweh, the Lord of all the earth, rest in the waters of the Jordan, that the waters of the Jordan will be cut off. The waters that come down from above shall stand in one heap.”

When the people moved from their tents to pass over the Jordan, the priests who bore the ark of the covenant being before the people,