'Edge' in the Bible

From Aroer, which is on the edge of the valley of the Arnon, and from the city that is in the valley, even unto Gilead, there was not a city too high for us; Jehovah our God delivered up all before us:

from Aroer, which is on the edge of the valley of the Arnon, even unto mount Sion (the same is Hermon),

thou shalt surely smite the inhabitants of that city with the edge of the sword, destroying it utterly, and all that is therein and the cattle thereof, with the edge of the sword.

and when Jehovah thy God delivereth it into thy hand, thou shalt smite every male thereof with the edge of the sword: