Joshua 22:27-28, 34

but as a memorial. It will remind our descendants and your descendants that we, too, have the right to worship the LORD at his sanctuary with our burnt offerings, sacrifices, and peace offerings. Then your descendants will not be able to say to ours, ‘You have no claim to the LORD.’ “If they say this, our descendants can reply, ‘Look at this copy of the LORD’s altar that our ancestors made. It is not for burnt offerings or sacrifices; it is a reminder of the relationship both of us have with the LORD.’

The people of Reuben and Gad named the altar “Witness,” for they said, “It is a witness between us and them that the LORD is our God, too.”