'Border' in the Bible

Thus says Yahweh: "For three transgressions of the children of Ammon, yes, for four, I will not turn away its punishment; because they have ripped open the pregnant women of Gilead, that they may enlarge their border.

Go to Calneh, and see; and from there go to Hamath the great; then go down to Gath of the Philistines. are they better than these kingdoms? or is their border greater than your border?