Joshua 22:18, commentary and pictures

Gad, Reuben, and half Manasseh received their inheritance before crossing the Jordan, choosing the wide upland plains and rich forests of Gilead and Bashan for grazing their flocks and herds, and they pledged their proportion of armed men to go with their brethren across the Jordan and share their battles. That pledge was faithfully kept when forty thousand prepared for war passed over to the plains of Jericho and fought bravely for years, then returned with much riches, very much cattle, silver, gold, brass, iron, and very much raiment to share with those who had remained with the families and flocks. Their departure was watched with anxious foreboding because they were now to dwell at a distance from the sanctuary, where isolated and wandering life beside bordering heathen tribes would bring strong temptations to fall into heathen customs.

The warning was spoken to Reuben, Gad, and the eastern tribes for erecting a large altar near the Jordan, which the congregation west of the Jordan supposed was meant to take the place of the tabernacle at Shiloh and would lead the people away from the true faith. It warns not to turn away this day from following the Lord in rebellion, because rebelling today will bring His wrath and anger tomorrow upon the whole congregation of Israel. That warning was enforced by the terrible judgments for joining Baal-Peor and by Achan, whose single transgression caused all Israel to suffer, to show how much more dire the result would be if that large company disobeyed. For that reason they were offered a share in the possessions and privileges on the west side if they were unwilling to remain in their own land without an altar for sacrifice and worship.

The concern behind the warning was sharpened by Achan's sin and God's rebuke for failure to detect it, but zeal to prevent sin led to judging the brethren before courteously asking what had happened. Fear of a perceived departure from true worship led to rebuking the brethren, but the suspected defection was a misunderstanding that might have caused disastrous division.