Carl Friedrich Keil and Franz Delitzsch Old Testament Commentary

47 Jehovah liveth, and blessed is my rock, And the God of my refuge of salvation is exalted. 48 The God who giveth me vengeance, And bringeth nations under me; 49 Who leadeth me out from mine enemies, And exalteth me above mine adversaries, Delivereth me from the man of violence. The formula חי־יהוה does not mean "let Jehovah live," for the word יחי would be used for that (vid., Sa2 16:16; Sa1 10:24), but is a declaration: "the Lord is living." The declaration itself is to be taken as praise of God, for "praising God is simply ascribing to Him the glorious perfections which belong to him; we have only to give Him what is His own" (Hengstenberg). The following clauses also contain simply declarations; this is evident from the word ירוּם, since the optative ירם would be used to denote a wish. The Lord is living or alive when He manifests His life in acts of omnipotence. In the last clause, the expression צוּר (rock) is intensified into ישׁעי צוּר אלהי (the God of my refuge, or rock, of salvation), i.e., the God who is my saving rock (cf. Sa2 22:3). In the predicates of God in Sa2 22:48, Sa2 22:49, the saving acts depicted by David in vv. 5-20 and 29-46 are summed up briefly. Instead of מוריד, "He causes to go down under me," i.e., He subjects to me, we find in the psalm ויּדבּר, "He drives nations under me," and מפלטי instead of מוציאי; and lastly, instead of חמס אישׁ in the psalm, we have here חמסים אישׁ, as in Psa 140:2. Therefore the praise of the Lord shall be sounded among all nations.