22:1-6 These verses bring to fruition 1:12-18 and the promise made by the two and a half tribes from east of the Jordan River to follow Joshua wherever he led. They had been faithful to their oath, so Joshua sent them home with his blessing.
22:7-8 The people received material blessings, even though this was not the main motivation for assisting their fellow tribes.
22:9-10 The tribes on the eastern side of the Jordan River built a large, impressive altar by the river. The altar that these tribes constructed is in Hebrew, mizbeach, a word that means “slaughter.” This is what caused the concern of the other tribes: animal sacrifice would take place on this altar.
22:11-12 Because the altar was beside the Jordan River and was so large, the ten tribes could probably see it. The rest of Israel assembled against the two and a half tribes to war against them from their base at Shiloh.
22:13 How much later this took place is not clear, but Phinehas son of Eleazar the priest was now the acting priest. He had last appeared in Nm 31:6 where he took articles from the sanctuary into battle.
22:14-19 The ten representatives of the remaining tribes objected because the altar was considered a competitor to the true altar of the Lord our God.
22:17 The iniquity of Peor refers to the time when Israel joined Midian in worshiping the Baal or god of the region of Peor, east of the Jordan River. In Nm 25:1-13 Phinehas executed God’s judgment for this sin by killing an Israelite man and a Midianite woman who were engaged in this carnal ritual.
22:21-25 The two and a half tribes explained they had built the altar as a way to maintain the unity of all the tribes in future generations.
22:27-28 The altar bore witness that those on both sides of it worshiped the same God at the same tabernacle. When Abram first came into the promised land, he built altars from north to south as a testimony that the land belonged to God and was his to give to Abram and his descendants (Gn 12:6-8; 13:18). Now the Transjordanian tribes had done the same thing. Although their land was not part of the promised land, they wanted to identify with the God of the promised land and to show that their land was a place where God was worshiped.
22:30-34 With the conflict resolved, the altar was named in recognition of the confession of the Transjordanian tribes.