Because God is truly glorious, and idols are vanity, the Psalmist exhorteth to confidence in him. God is to be praised for his blessings.
THERE is great reason to think that this psalm was composed in some time of great distress, when the pagan enemies of the Jews began to boast as if their gods were too powerful for the God of Israel: but by whom it was made, or on what particular occasion, there are so many conjectures, says Bishop Patrick, that it will be no presumption to interpose mine, which is this: that when Jehoshaphat saw the vast army which we read of, 2 Chronicles 20:2 composed of several nations, coming against him, and, after his prayer to God for deliverance, was encouraged by a prophet to hope for it, (Psalms 115:14-15.) and had by the Levites given Jehovah thanks for this hope, he or that prophet composed this hymn to quicken and confirm the people's faith in God, to which you read he exhorted them, 2 Chronicles 20:20 and it is not unlikely that this was the hymn which, by common consent, the singers were appointed to use when they went to encounter those enemies; saying not only those words which were read there, (2 Chronicles 20:21.) praise the Lord, &c. but these also, Not unto us, O Lord, &c. Dr. Delaney however is of opinion, that this psalm was composed as an epinicion or triumphal song for David's victory over the Jebusites; the lame and the blind, &c. (see 2 Samuel 5:6.) it being plainly a hymn of humiliation and thanksgiving to God for a victory gained over a heathen people, who put their confidence in their idols, and despised the God of David: (see from Psalms 115:2-8.) And, however this hymn may be adapted to the people of the Jews by many peculiarities, yet it is remarkable, that it has always been used as a hymn of thanksgiving for victories by all princes of true piety from the earliest Christian ages, and very probably from the age of David. See Life of David, book 2: chap. 6.
Psalms 115:1. Not unto us, O Lord— By the repetition of these words the Psalmist humbly expresses the unworthiness of the Jews to receive the signal blessings wherewith the Lord had favoured them.