Albert Barnes Commentary Job 5:15

"But he saveth from the sword of their mouth, Even the needy from the hand of the mighty." — Job 5:15 (ASV)

But he saves the poor from the sword - He shows himself to be the friend and protector of the defenseless. The phrase “from the sword, from their mouth,” has been variously interpreted. Dr. Good renders it:
“So he saves the persecutors from their mouth,
And the helpless from the hand of the violent.”

Noyes renders it:
“So he saves the persecuted from their mouth,
The oppressed from the hand of the mighty.”

This rendering is obtained by changing the points in the word מחרב mēchereb—“from the sword,”—to מחרב māchĕrāb—making it the Hophal participle from חרב chârab—to make desolate. This was proposed by Capellus and has been adopted by Durell, Michaelis, Dathe, Doederlein, and others. Rosenmuller pronounces it wholly unauthorized.

Jerome renders it, a gladio otis eorum—“from the sword of their mouth.” It seems to me that the whole verse may be literally rendered, “he saves from the sword, from their mouth, and from the hand of the strong, the poor.” According to this version, the phrase “from their mouth” may mean either from the mouth (i.e., the edge of the sword, using the plural for the singular) or from the mouth of oppressors, using it to represent their violence and their disposition to devour the poor. The latter is more probably the true interpretation, and there is no need of a change in the points in the Hebrew.

Thus interpreted, the sense is that God preserves the poor from oppression, or, in other words, that he befriends them and is therefore worthy of confidence. This sentiment accords with what is found everywhere in the Bible.