'Edge' in the Bible

From Aroer which is on the edge of the valley of Arnon and from the city which is in the valley, even to Gilead, there was no city that was too high for us; the Lord our God delivered all over to us.

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

you shall surely strike the inhabitants of that city with the edge of the sword, utterly destroying it and all that is in it and its cattle with the edge of the sword.

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