So the sons (descendants) of Reuben and the sons of Gad and the half-tribe of Manasseh returned home and departed from the [other] sons (western tribes) of Israel at Shiloh which is in the land of Canaan, to go to the land of Gilead, to the land of their own which they had possessed, in accordance with the command of the LORD through Moses.
When they came to the region of the Jordan which is in the land of Canaan, the sons of Reuben and the sons of Gad and the half-tribe of Manasseh built an altar there by the Jordan, an altar that was great to behold. And the [other] sons of Israel heard it said, “Look, the sons of Reuben and the sons of Gad and the half-tribe of Manasseh have built an altar at the edge of the land of Canaan, in the region [west] of the Jordan, on the side belonging to the sons of Israel.” When the sons of Israel heard of it, the whole congregation of the Israelites gathered at Shiloh to make war against them.
Then the sons of Israel sent Phinehas the son of Eleazar the priest to the sons of Reuben and the sons of Gad and the half-tribe of Manasseh, in the land of Gilead, and with him ten leaders, one leader from each father’s household from each of the tribes of Israel; and each one was the head of his father’s household among the thousands of Israel. They came to the sons of Reuben and the sons of Gad and the half-tribe of Manasseh, in the land of Gilead, and they said to them, “This is what the entire congregation of the LORD says, ‘What is this disloyal and unfaithful act which you have committed against the God of Israel, so as to turn away from following the LORD this day, by building yourselves an altar, to rebel against the LORD this day? Is the wrongdoing (idolatry) of Peor not enough for us, from which we have not cleansed ourselves to this day, even though the affliction [in which twenty-four thousand died] came on the congregation of the LORD, [Num 25:1-9] that you would turn away this day from following the LORD? If you rebel against the LORD today, He will be angry with the entire congregation of Israel tomorrow. If, however, the land of your possession is unclean, then cross into the land of the possession of the LORD, where the LORD’S tabernacle is situated, and settle down among us. But do not rebel against the LORD, or rebel against us by building an altar for yourselves, besides the altar of the LORD our God [at Shiloh]. Did not Achan the son of Zerah act unfaithfully in the things under the ban, and [as a result God’s] wrath came on the entire congregation of Israel? And that man did not perish alone in his wrongdoing.’ ” [Josh 7:1-26]