'Fall by the Sword' in the Bible

Why does Yahweh bring us to this land, to fall by the sword? Our wives and our little ones will be a prey: wouldn't it be better for us to return into Egypt?"

For there the Amalekite and the Canaanite are before you, and you shall fall by the sword: because you are turned back from following Yahweh, therefore Yahweh will not be with you."