Matthew Poole and continuators on Psalms 45:5

5. Thine arrows are sharp in the heart of the kings enemies : whereby the people fall under thee .

The same thing, for Substance with the Sword, v. 3. both noting the Instruments by which he Conquers his Enemies; which is no other than his Word, which is sharp and powerful, and pierceth the Hearts of Men, Heb. 4. 12. which also first wounds Sinners, and then heals them; and which is for the Fall, as well as for the Rising of many, Luk. 2. 34: and for Iudgment, as well as for Mercy, Ioh. 9. 39. to some a Savour of Death, and to others a Savour of Life, 2 Cor. 2. 16. and therefore is fitly Compared to Arrows; which Title is sometimes given to words, as Psal, 64. 4. and frequently to God's Plagues or Judgments, Deut. 32. 23. Psal. 18. 14. and 64. 7. such as the Word becomes to ungodly Men by their own Fault. And these Metaphorical Weapons are oft ascribed to Christ; who hath a Bow, Revel. 6. 2. and Weapons of Warfare, 2 Cor. 10. 4. and whose Mouth God is said to make a Sword, and an Arrow, Isa 49. 2.

(i. e.) Of thine Enemies; the third Person being put for the second, as is usual in Prophetical Writings; which here may seem to have some Emphasis▪ as describing the Persons, against whom he shot his Arrows, and the Reason why he did so, because they were the Enemies of his Kingdom, and would not have him to Reign over them, Luk. 19. 27.

Either, as slain by thine Arrows; Or, as prostrate at thy Feet, after the manner of Conquered Persons, Psal. 18. 38. and 20. 8. According to this and many other Translations, the Words are Transplaced, which in the Hebrew lye thus, Thine Arrows are sharp, whereby the People do fall under thee, in the Heart, (i. e. in the midst, which is oft called the Heart, as Exod. 15. 8. Deut. 4. 11. And so it may be here; for the Army▪ as such, hath no Heart, Properly so called. And so this is fitly alledged, as a Proof of the sharpness and force of his Arrows that they not onely wound those who march in the Front, but even those who are in the midst of the Army, where they may seem secure, and out of their Reach) of the Kings Enemies. But the middle Words may be, and are by many included within a Parenthesis, and so they may agree with our Translation thus, Thine Arrows are sharp (for the People fall under thee, which is an Evidence of their sharpness) in the Heart (or against the Heart; Or, piercing into the Heart. Which is an easie and usual Ellipsis) of the Kings Enemies.