Joshua 22:34

And the children of Reuben, and the children of Gad, called the altar [Ed],.... Which signifies a "witness"; they caused such an inscription to be put upon it, or this word to be engraved on it, that so the intention of erecting it might be known in future time; that it was not for sacrifice, but to be a testimony of their being one with their brethren on the other side Jordan, in worship, faith, and fellowship:

for [it shall be] a witness between us that the Lord [is] God; is the one God, the God of them both, of all Israel, whether on the one or the other side of Jordan; to be worshipped by them in one and the same manner, and their sacrifices to be offered to him on his altar before the tabernacle.