Joshua 22:27

“But [that] it [may be] a witness between us and you, and our generations after us, etc.] That we are one people, worship one God, and serve at one altar, of which this built was a resemblance, and would put them in mind of it: that we might do the service of the Lord before him; in the tabernacle, and at the altar, in the place where he had chosen to put his name and dwell: with our burnt offerings, and with our sacrifices, and with our peace offerings; to be brought at stated times, or as occasion required: that your children may not say to our children, in time to come, ye have no part in the Lord; nor right to his altar, and so forbid them offering their sacrifices on it; or “have no part…”

“Before him - That we and ours may have and hold our privilege of serving and worshiping God, not upon this altar, but in the place of God's presence, in your tabernacle, and upon your altar. Joshua 22:28”

“22:27 The altar near the bank of the Jordan would stand as a memorial (literally witness) through the generations that the eastern tribes were also part of Israel.”

“a witness: Jos 22:10, Jos 22:34, Jos 24:27; Gen 31:48, Gen 31:52; Sa1 7:12 that we: Deu 12:5, Deu 12:6, Deu 12:11, Deu 12:17, Deu 12:18, Deu 12:26, Deu 12:27 Joshua 22:28”