Joshua 3:3-5
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.”
3:5 Joshua told the people, “Ritually consecrate yourselves, for tomorrow the Lord will perform miraculous deeds among you.”