'Edge' in the Bible

From Aroer, which is on the edge of the Arnon Valley, and from the city which is in the valley, as far as Gilead, there was no city [whose wall was] too high and too strong for us; the Lord our God handed over everything to us.

“So we took possession of this land at that time. I gave the territory from Aroer, which is by the valley of the Arnon, along with half of the hill country of Gilead and its cities to the Reubenites and to the Gadites.

from Aroer, which is on the edge of the valley of the [river] Arnon, as far as Mount Sion (that is, Hermon),

you shall most certainly strike the inhabitants of that city with the edge of the sword, utterly destroying it and all that is in it, even its livestock with the edge of the sword.

When the Lord your God gives it into your hand, you shall strike down all the men in it with the edge of the sword.