The allusions to the ancient promise are completed in vv. 36, 37, with the thought of the perpetual continuance of the Davidic line and kingdom, expressed by the familiar comparison of its duration to that of the sun and moon. Ver. 37 _b_ is best understood as above. Some take the faithful witness to be the moon; others the rainbow, and render, as in the A.V. and R.V., "and as the faithful witness." But the designation of the moon as a witness is unexampled and almost unintelligible. It is better to take the clause as independent, and to suppose that Jehovah is His own witness, and that the psalmist here speaks in his own person, the quotation of the promises being ended. Cheyne encloses the clause in a parenthesis and compares Rev. iii. 14.
The third part begins with ver. 38, and consists of two portions, in the first of which the psalmist complains with extraordinary boldness of remonstrance, and describes the contrast between these lofty promises and the sad reality (vv. 38-45), and, in the second prays for the removal of the contradiction of God's promise by Israel's affliction, and bases this petition on the double ground of the shortness of life, and the dishonour done to His own Name thereby.
The expostulation very nearly crosses the boundary of reverent remonstrance, when it charges God with having Himself "abhorred" or, according to another rendering, "made void" His covenant, and cast the king's crown to the ground. The devastation of the kingdom is described, in vv. 40, 41, in language borrowed from Psalm lxxx. 12. The pronouns grammatically refer to the king, but the ideas of the land and the monarch are blended. The next pair of verses (42, 43) ventures still further in remonstrance, by charging God with taking the side of Israel's enemies and actively intervening to procure its defeat. The last verse-pair of this part (44, 45) speaks more exclusively of the king, or perhaps of the monarchy. The language, especially in ver. 45 _a_, seems most naturally understood of an individual. Delitzsch takes such to be its application, and supposes it to describe the king as having been prematurely aged by calamity; while Hupfeld, with Hengstenberg and others, prefer to regard the expression as lamenting that the early days of the monarchy's vigour had so soon been succeeded by decrepitude like that of age. That family, which had been promised perpetual duration and dominion, has lost its lustre, and is like a dying lamp. That throne has fallen to the ground, which God had promised should stand for ever. Senile weakness has stricken the monarchy, and disaster, which makes it an object of contempt, wraps it like a garment, instead of the royal robe. A long, sad wail of the music fixes the picture on the mind of the hearer.
Then follows prayer, which shows how consistent with true reverence and humble dependence is the outspoken vigour of the preceding remonstrance. The boldest thoughts about the apparent contradiction of God's words and deeds are not too bold, if spoken straight to Him, and not muttered against Him, and if they lead the speaker to prayer for the removal of the anomaly. In ver. 46 there is a quotation from Psalm lxxix. 5. The question "How long" is the more imploring because life is so short. There is but a little while during which it is possible for God to manifest Himself as full of Loving-kindness and Faithfulness. The psalmist lets his feelings of longing to see for himself the manifestation of these attributes peep forth for a moment, in that pathetic sudden emergence of "I" instead of "we" or "men," in ver. 47 _a_. His language is somewhat obscure, but the sense is clear. Literally, the words read "Remember--I, what a transitoriness." The meaning is plain enough, when it is observed that, as Perowne rightly says, "I" is placed first for the sake of emphasis. It is a tender thought that God may be moved to show forth His Loving-kindness by remembrance of the brief period within which a man's opportunity of beholding it is restricted, and by the consideration that so soon he will have to look on a grimmer sight, and "see death." The music again comes in with a melancholy cadence, emphasising the sadness which enwraps man's short life, if no gleams of God's loving-kindness fall on its fleeting days.