Scofield Reference Notes (1917 Edition)Chapter 22
22:25 For the LORD hath made Jordan a border between us and you, ye children of Reuben and children of Gad; ye have no part in the LORD: so shall your children make our children cease from fearing the LORD.
22:34 And the children of Reuben and the children of Gad called the altar Ed: for it shall be a witness between us that the LORD is God.
(See Scofield "Psalms 19:9") .
i.e. a witness; so Joshua 24:27.