Numbers 1:53

53But the Levites shall camp around the tabernacle of the testimony, so that there may be no awrath on the congregation of the people of Israel. bAnd the Levites shall keep guard over the tabernacle of the testimony.”

Numbers 2:17

17 c“Then the tent of meeting shall set out, with the camp of the Levites in the midst of the camps; as they camp, so shall they set out, each in position, standard by standard.

Joshua 3:4

4 dYet there shall be a distance between you and it, about 2,000 cubits
A  cubit was about 18 inches or 45 centimeters
in length. Do not come near it, in order that you may know the way you shall go, for you have not passed this way before.”
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