The eastern tribes explain

21Then the sons of Reuben, the sons of Gad, and the half-tribe of Manasseh answered and spoke to the heads of the clans of Israel:

22The Mighty One, God, Yahweh! The Mighty One, God, Yahweh! He knows, and Israel itself will know: if it was in rebellion, or if in unfaithfulness against Yahweh, do not save us this day.

23if we built for ourselves an altar to turn away from following Yahweh, or if to offer on it burnt offering or grain offering, or if to make on it sacrifices of peace offerings, may Yahweh himself require it.

24No, rather, we did this out of anxious concern, saying, ‘In time to come your children may say to our children, “What have you to do with the LORD, the God of Israel?”’

25For Yahweh has made the Jordan a boundary between us and you, sons of Reuben and sons of Gad. You have no portion in Yahweh. And so your sons might cause our sons to stop fearing Yahweh.