Now these are the kings of the land, which the children of Israel smote, and possessed their land on the other side Jordan toward the rising of the sun, from the river Arnon unto mount Hermon, and all the plain on the east: From the river Arnon unto Mount Hermon - Arnon was the boundary of all the southern coast of the land occupied by the Israelites beyond Jordan; and the mountains of Hermon were the boundaries on the north. Arnon takes its rise in the mountains of Gilead, and having run a long way from north to south falls into the Dead Sea, near the same place into which Jordan discharges itself.
And all the plain on the east - All the land from the plains of Moab to Mount Hermon.