By this I know that I have been acceptable to thee David now proceeds to the exercise of thanksgiving; unless, indeed, by altering the tense of the verb, we would rather with some read this verse in connection with the preceding, in this way: In this I shall know that thou favorest me, if thou suffer not my enemies to triumph over me; but it suits much better to understand it as an expression of joy on account of some deliverance which God had vouchsafed to him. After having offered up his prayers, he now ascribes his deliverance to God, and speaks of it as a manifest and singular benefit he had received from him. It might, however, be asked, whether it is a sufficiently sure method of our coming to the knowledge of God's love towards us, that he does not suffer our enemies to triumph over us? for it will often happen, that a man is delivered from danger, whom, nevertheless, God does not regard with pleasure; and, besides, the good-will of God towards us is known chiefly from his word, and not simply by experience. The answer to this is easy: David was not destitute of faith, but for the confirmation of it he took advantage of the helps which God had afterwards added to his word. In speaking thus, he seems to refer not only to the favor and good-will which God bears to all the faithful in common, but to the special favor which God had conferred upon him in choosing him to be king; as if he had said, Now, Lord, I am more and more confirmed in the belief that thou hast vouchsafed to adopt me to be the first-born among the kings of the earth. Thus he extends to the whole state of the realm the help of God, by means of which he had been delivered from some particular calamity.

By this I know - Compare the notes at Psalm 20:6. This indicates a confident assurance that his prayer would be answered, and that he would be restored to health. How he had this assurance we are not informed, but it seems most probable that it was by an intimation conveyed to his mind by God himself. Compare, for a similar case, Philippians 1:25. See the notes at that passage.
That thou favorest me - That thou dost delight in me; that thou art my friend.
Because mine enemy doth not triumph over me - The word here rendered triumph properly means to shout, or to make a noise. As a sign of exultation, more especially in war: 1-Samuel 17:20. Here it means that his enemy would not secure a victory over him; or would not shout as if such a victory were obtained. That is, he felt assured now that all the machinations of his goes would be defeated; that all the hopes which they cherished that he was soon to die would be disappointed; that he himself would be recovered from Iris sickness, contrary to their malicious anticipations and desires. This he regarded as an evidence that God was his friend.

By this I know that thou favorest me - If thou hadst not been on my side, I had perished by this disease; and then my enemies would have had cause to triumph.
This also has been applied to our Lord; and Calmet says it is the greatest proof we have of the divinity of Christ, that he did not permit the malice of the Jews, nor the rage of the devil, to prevail against him. They might persecute, blaspheme, mock, insult, crucify, and slay him; but his resurrection confounded them; and by it he gained the victory over sin, death, and hell.

By this I know that thou favourest me,.... Or "delightest in me" (z); as he did, both as his Son and his servant; in his obedience, sufferings, and death, whereby his counsels were accomplished, his covenant ratified, and the salvation of his people procured; and which delight and well pleasedness in him was the ground of his deliverance from the power of death and the grave; see Psalm 18:19; the token by which Christ knew this was,
because mine enemy doth not triumph over me; Judas could not; he was too short lived, he was quickly taken away, and all the woes fall upon him imprecated on him, Psalm 109:6; nor the Jews; for though they were highly delighted when they had fastened him to the cross, and when he was dead, and laid in the grave; yet they could not sing their jubilee song over him until the third day was past; for they knew he had given out that he should rise again the third day; on which day he did rise, and his apostles preached that he was alive, and through him the resurrection of the dead, to their great grief, vexation, and mortification: nor did Satan, the enemy of Christ, personal and mystical, triumph over him; not in the wilderness, where, after he had tempted him, he was obliged to leave him; nor in the garden, and his agony there, where he was strengthened by an angel; nor even on the cross; for on that Christ himself triumphed over Satan and his principalities, whom he spoiled, and destroyed the devil and all his works; and, at his ascension to heaven, led captivity captive, and gave gifts to men, in token of triumph, and went forth, in the ministration of the Gospel, conquering, and to conquer; turning men from the power of Satan, and causing his servants to triumph in him, while they were in every place diffusing the savour of his knowledge.
(z) "complacuisti in me", Pagninus, Montanus, Vatablus; "delectaris me", Junius & Tremellius, Piscator, Cocceius.

favourest--or tenderly lovest me (Genesis 34:19), evinced by relief from his enemies, and, farther, God recognizes his innocence by upholding him.

By this - Because hitherto thou hast supported me, and prolonged my days to the disappointment of their hopes.