As for me, I am poor and sorrowful. [1] From this verse we perceive more distinctly how David cast away from him the swelling and raging passion of those who, with ungovernable fury, pour forth imprecation and vengeance. He here, without doubt, offers himself to God with the sacrifice of a broken and humble heart, that by this meekness of spirit he may obtain favor with him. He therefore adds immediately after, Thy salvation shall exalt me. Those assuredly who are impelled to avenge themselves by their own ungovernable spirits are so far from being humbled, that they exalt themselves to a position to which they are not entitled. There is here a mutual relation stated between the sorrow with which he was oppressed, and the help of God by which he hoped to be lifted up. At the same time, he assures himself that the very thing which others considered as a ground for despair, would prove to him the cause of his salvation. This sentence might also be explained adversatively thus: Although I now mourn under the pressure of affliction, yet shall thy salvation, O Lord! exalt me. But for my part, I consider it certain that David brings forward his own affliction as a plea for obtaining mercy at the hand of God. Nor does he say simply that he will be raised up, but he expressly speaks of being exalted; and in this he alludes to fortresses which are set upon high places; for this is the proper signification of the Hebrew word sgv, sagab, here employed.

Footnotes

1 - Boothroyd reads, "humbled and afflicted!"

But I am poor and sorrowful - I am afflicted and suffering. The word here rendered "poor" often means "afflicted."
Let thy salvation, O God, set me up on high - Let thy help raise me up from my low condition, and exalt me to a place of safety.

I am poor and sorrowful - Literally, I an laid low, and full of pain or grief. Hence the prayer, "Let thy salvation, O God set me on high!" My oppression has laid me low; thy salvation shall make me high!

But I am poor and sorrowful,.... The Messiah was poor in a literal sense, as it was foretold he should, Zac 9:9; so he was in his private life; born of poor parents, and brought up in a mean way: and in his public life, having no certain dwelling place, and ministered to by others; and when on the cross, being stripped of his garments; and nothing to eat and drink but gall and vinegar; and nothing to leave to his mother, but commits her to the care of his beloved disciple. Though this phrase in general may denote the low estate of Christ in his humiliation, being in the form of a servant, humbled and obedient to death; and the character of "sorrowful" well agrees with him, who was a man of sorrows all his days; and in the garden his soul was exceeding sorrowful, even unto death; and when on the cross he had sorrow enough; what with the sins of his people on him, the flouts and jeers of his enemies at him; the pains of body he endured, the wrath of God, the hidings of his face, and the curses of his righteous law. After this declaration of his low and distressed state, a petition follows:
let thy salvation, O God, set me up on high: meaning either the salvation of the Lord's people, so called, because concerted and appointed of God, and is what he sent his Son to effect, and he approves of; this being wrought out was the way and, means of the exaltation of Christ; both by his divine Father, who on this account exalted him at his right hand; and by his people, who exalt him in their hearts, and with their tongues, and give him all the glory of their salvation. Or else this means the salvation of Christ out of the hands of all his enemies, whom he conquered on the cross; and particularly death, from which he was saved by his resurrection, and was the first step to his exaltation and glory; after which he ascended on high, and sat down at the right hand of God; where no mere creature, angels or men, were ever admitted; and where angels, principalities, and powers, are subject to him. The whole may be rendered thus; "though I am poor and sorrowful, thy salvation, O God, will set me up on high" (o); and so is expressive of the Messiah's faith in his resurrection and exaltation, notwithstanding his sorrows and sufferings; on account of which he determines to praise the Lord, as follows.
(o) "elevabit me", Pagninus, Montanus; so Gejerus, Michaelis.

poor and sorrowful--the afflicted pious, often denoted by such terms (compare Psalm 10:17; Psalm 12:5).
set me . . . high--out of danger.

On high - Out of the reach of mine enemies.