Exodus 25:14

25:14 and put the poles into the rings at the sides of the ark in order to carry the ark with them.

Exodus 27:7

27:7 The poles are to be put into the rings so that the poles will be on two sides of the altar when carrying it.

Exodus 37:5

37:5 and put the poles into the rings on the sides of the ark in order to carry the ark.