Joshua 3:1-6

And Joshua rose up early in the morning; and they removed from Shittim, and came to the Jordan, he and all the children of Israel; and they lodged there before they passed over. And it came to pass after three days, that the officers went through the midst of the camp; and they commanded the people, saying, When ye see the ark of the covenant of Jehovah your God, and the priests the Levites bearing it, then ye shall remove from your place, and go after it. Yet there shall be a space between you and it, about two thousand cubits by measure: come not near unto it, that ye may know the way by which ye must go; for ye have not passed this way heretofore. And Joshua said unto the people, Sanctify yourselves; for to-morrow Jehovah will do wonders among you. And Joshua spake unto the priests, saying, Take up the ark of the covenant, and pass over before the people. And they took up the ark of the covenant, and went before the people.