They had prevented me in the day of my calamity. [1] The Psalmist here confirms in different words the preceding sentence, namely, that he had been sustained by the aid of God, when there was no way of escaping by the power of man. He tells us how he had been besieged on all sides, and that not by an ordinary siege, inasmuch as his enemies, in persecuting him, always molested him most in the time of his calamity. From this circumstance it is the more evident that he had obtained enlargement by no other means than by the hand of God. Whence proceeded so sudden a restoration from death to life, but because God intended to show that he has in his hand, and under his absolute control, the issues of death? In short, the Psalmist ascribes his deliverance to no other cause than the mere good pleasure of God, that all the praise might redound to him alone: He delivered me, because he loved me, or had a good will to me. In mentioning the good pleasure of God, he has a special respect to his own calling to be king. The point on which he principally insisted is, that the assaults which were made upon him, and the conflicts which he had to sustain, were stirred up against him for no other reason but because he had obeyed the call of God, and followed with humble obedience the revelation of his oracle. Ambitious and turbulent men, who are carried headlong by their unruly lusts, inconsiderately to attempt any thing, and who, by their rashness, involve themselves in dangers, may often accomplish their undertakings by vigorous and resolute efforts, but at length a reverse takes place, and they are stopt short in their career of success, for they are unworthy of being sustained and prospered by God, since, without having any warrant or foundation for what they do in his call, they would raise their insane structures even to heaven, and disturb all around them. In short, David testifies, by this expression, that the assistance of God had never failed him, because he had not thrust himself into the office of king of his own accord, but that when he was contented with his humble condition, and would willingly have lived in obscurity, in the sheep-cotes, or in his father's hut, he had been anointed by the hand of Samuel, which was the symbol of his free election by God to fill the throne.

Footnotes

1 - "They set their faces against me in the day of my calamity," -- Walford.

They prevented me - They anticipated me, or went before me. See the note at Psalm 18:5. The idea here is that his enemies came before him, or intercepted his way. They were in his path, ready to destroy him.
In the day of my calamity - In the day to which I now look back as the time of my special trial.
But the Lord was my stay - My support, or prop. That is, the Lord upheld me, and kept me from falling.

They prevented me in the day of my calamity - They took advantage of the time in which I was least able to make head against them, and their attack was sudden and powerful. I should have been overthrown, but the Lord was my stay. He had been nearly exhausted by the fatigue of the day, when the giant availed himself of this advantage.

They prevented me in the day of my calamity,.... Referring to the times of his distress in the garden and upon the cross; the time of his sufferings and death, which was a dark and cloudy day, as the word (x) used suggests, both in a literal and in a spiritual sense; and when the day and hour was come, fixed and determined by the will of God, then his enemies, though not before, met him, laid hold on him, were too mighty for him, condemned, crucified, and insulted him;
but the Lord was my stay; or staff, on whom he leaned, relied, and depended, believing he would help him; and by whom he was supported and upheld, Isaiah 42:1. The Targum is,
"the Word of the Lord was my stay.''
(x) "in the day of my cloudy calamity", Ainsworth; "nomen" "proprie signifient vaporem vel nubem, ut Genesis. vii. 6. hinc per metaphoram transfertur ad obscuras ac terrificas calamitatum nebulas, Prov. i. 26.", Gejerus.

prevented-- (Psalm 18:3).

Prevented - They had almost surprized me.