المزامير ٨٩:٣٤

Contrasting man's frailty with God's eternity, the writer mourns over it as the punishment of sin, and prays for a return of the divine favor. A Prayer [mainly such] of Moses the man of God-- (Deu 33:1; Jos 14:6); as such he wrote this (see on Psa 18:1, title, and Psa 36:1, title). (Psa. 90:1-17) dwelling-place--home (compare Eze 11:16), as a refuge (Deu 33:27).

Once have I sworn by my holiness,.... Swearing is ascribed to God after the manner of men, and is done in condescension to the weakness of his people, and to remove doubts and hesitations from them, relating to things spiritual and eternal; as to his everlasting love to them, his covenant with them in Christ, and their perseverance in his grace; and it is made by himself, or one or other of his perfections, as here by his "holiness"; see Amo 4:2, and indeed his holiness being his nature, is no other than he himself, the holy God; and because he could swear by no greater, he sware by himself, that as sure as he was, and was holy, just, and true, he would make good what he promises, Heb 6:13 and this is done but once, once for all, that being sufficient; it need not be repeated, nor is it ever revoked; when he swears, he never repents of it, nor changes his mind; and it is to show the immutability of his counsel that he swears at all, Psa 110:4, that I will not lie unto David; he will not lie to any, he cannot, it is impossible he should; it would be to deny himself, it is contrary to his being as God, he is not a man that he should lie; it is contrary to his character as the God of truth; he will not lie, neither in his counsel nor covenant, in his purposes nor promises; these are the two immutable things, in which it is impossible he should lie: and he has swore to it that he will not lie to David, to David's son the Messiah, with whom the covenant is made, and stands fast; all the prophecies concerning him he has fulfilled; and all the promises made to him of help and assistance, as man and Mediator, in his work, and of the reward of it, a glory with him, he has made good.

Many psalms that begin with complaint and prayer end with joy and praise, but this begins with joy and praise and ends with sad complaints and petitions; for the psalmist first recounts God's former favours, and then with the consideration of them aggravates the present grievances. It is uncertain when it was penned; only, in general, that it was at a time when the house of David was woefully eclipsed; some think it was at the time of the captivity of Babylon, when king Zedekiah was insulted over, and abused, by Nebuchadnezzar, and then they make the title to signify no more than that the psalm was set to the tune of a song of Ethan the son of Zerah, called Maschil; others suppose it to be penned by Ethan, who is mentioned in the story of Solomon, who, outliving that glorious prince, thus lamented the great disgrace done to the house of David in the next reign by the revolt of the ten tribes. I. The psalmist, in the joyful pleasant part of the psalm, gives glory to God, and takes comfort to himself and his friends. This he does more briefly, mentioning God's mercy and truth (Psa 89:1) and his covenant (Psa 89:2-4), but more largely in the following verses, wherein, 1. He adores the glory and perfection of God (Psa 89:5-14). 2. He pleases himself in the happiness of those that are admitted into communion with him (Psa 89:15-18). 3. He builds all his hope upon God's covenant with David, as a type of Christ (v. 19-37). II. In the melancholy part of the psalm he laments the present calamitous state of the prince and royal family (Psa 89:38-45), expostulates with God upon it (Psa 89:46-49), and then concludes with prayer for redress (Psa 89:50, Psa 89:51). In singing this psalm we must have high thoughts of God, a lively faith in his covenant with the Redeemer, and a sympath…