'Middle' in the Bible

To the Reubenites and to the Gadites I gave from Gilead even as far as the valley of Arnon, the middle of the valley as a border and as far as the river Jabbok, the border of the sons of Ammon;

Then you shall gather all its booty into the middle of its open square and burn the city and all its booty with fire as a whole burnt offering to the Lord your God; and it shall be a ruin forever. It shall never be rebuilt.