'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 to Gilead, there was not a city too high for us; Yahweh our God delivered up all before us:

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

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

and when Yahweh your God delivers it into your hand, you shall strike every male of it with the edge of the sword: