Joshua 3:3-6

3and they charged the people saying, “When you see the ark of the covenant of Adonai your God and the Levitical kohanim carrying it, then you must set out from your place and follow it.

4Yet keep a distance between you and it of about 2,000 cubits by measure. Don’t come near it, so you may know the way by which you should go, for you haven’t travelled this way before.”

5Then Joshua told the people, “Consecrate yourselves, for tomorrow Adonai will do wonders in your midst.”

6Joshua spoke to the kohanim saying: “Take up the ark of the covenant and cross over ahead of the people.” So they took up the ark of the covenant and went ahead of the people.