The Reubenites, Gadites and half the tribe of Manasseh built an altar by the Jordan River after being given land east of the river. This alarmed the other Israelite tribes who gathered to go to war against them, thinking they had turned away from God. A delegation investigated and the tribes explained the altar was merely a witness to future generations that they too worshipped God, not for sacrifices which were only permitted at the tabernacle altar. The explanation satisfied the others and the altar was named "Witness."