This verse recounts the reaction of the Israelites upon hearing that the tribes of Reuben, Gad, and the half-tribe of Manasseh had built an altar near the Jordan River. Initially, the Israelites prepared for war, assuming that the altar was a sign of rebellion against the Lord. This incident highlights the importance of clear communication and unity among God's people to prevent misunderstandings and conflicts. It also serves as a reminder to seek understanding and reconciliation before jumping to conclusions or taking hasty actions. Ultimately, the situation was resolved peacefully after the tribes explained that the altar was not for sacrifices but as a witness of their unity with the rest of Israel.