Joshua 3:1-4
Israel Crosses the Jordan
3:1 Bright and early the next morning Joshua and the Israelites left Shittim and came to the Jordan. They camped there before crossing the river.
3:2 After three days the leaders went through the camp
3:3 and commanded the people: “When you see the ark of the covenant of the Lord your God being carried by the Levitical priests, you must leave here and walk behind it.
3:4 But stay about three thousand feet behind it. Keep your distance so you can see which way you should go, for you have not traveled this way before.”