The great act of judgment which the song celebrates is now (vs. 5, 6) brought into contrast with the blessed picture of the city, and by the introductory 'for' is stated as the reason for eternal trust. The language, as it were, leaps and dances in jubilation, heaping together brief emotional and synonymous clauses. So low is the once proud city brought, that the feet of the poor tread it down. These 'poor' and 'needy' are the true Israel, the suffering saints, who had known how cruel the sway of the fallen robber city was; and now they march across its site; and its broken columns and ruined palaces strew the ground below their feet. 'The righteous nation' of the one picture are 'the poor and needy' of the other. No doubt the prophecy has had partial accomplishments more than once or twice, when the oppressed church has triumphed, and some hoary iniquity been levelled at a blow, or toppled over by slow decay. But the complete accomplishment is yet future, and not to be realised till that last act, when all antagonism shall be ended, and the net result of the weary history of the world be found to be just these two pictures of Isaiah's--the strong city of God with its happy inhabitants, and the everlasting desolations of the fallen city of confusion.
The triumphant hurry of the song pauses for a moment to gaze upon the crash, and in verse 7 gathers its lessons into a kind of proverbial saying, which is perhaps best translated 'The path of the just is smooth (or "plain"); Thou levellest smooth the path of the just.' To render 'upright' instead of 'smooth' seems to make the statement almost an identical proposition, and is tame. What is meant is, that, in the light of the end, the path which often seemed rough is vindicated. The judgment has showed that the righteous man's course had no unnecessary difficulties. The goal explains the road. The good man's path is smooth, not because of its own nature, but because God makes it so. We are to look for the clearing of our road, not to ourselves, nor to circumstances, but to Him; and even when it is engineered through rocks and roughnesses, to believe that He will make the rough places plain, or give us shoes of iron and brass to encounter them. Trust that when the journey is over the road will be explained, and that this reflection, which breaks the current of the swift song of the prophet, will be the abiding, happy conviction of heaven.
Lastly, the song looks back and tells how the poor and needy, in whose name the prophet speaks, had filled the dreary past, while the tyranny of the fallen city lasted, with yearning for the judgment which has now come at last. Verses 8 and 9 breathe the very spirit of patient longing and meek hope. There is a certain tone of triumph in that 'Yea,' as if the singer would point to the great judgment now accomplished, as vindicating the long, weary hours of hope deferred. That for which 'the poor and needy' wait is the coming 'in the path of Thy judgments.' The attitude of expectance is as much the duty and support of Christians as of Israel. We have a greater future clearer before us than they had. The world needs God's coming in judgment more than ever; and it says little for either the love to God or the benevolence towards man of average Christians, that they should know so little of that yearning of soul which breathes through so much of the Old Testament. For the glory of God and the good of men, we should have the desire of our souls turned to His manifestation of Himself in His righteous judgments. It was no personal end which bred the prophet's yearning. True, the 'night' round him was dreary enough, and sorrow lay black on his people and himself; but it was God's 'name' and 'memorial' that was uppermost in his desires. That is to say, the chief object of the devout soul's longings should be the glory of God's revealed character. And the deepest reason for wishing that He would flash forth from His hiding-place in judgments, is because such an apocalypse is the only way by which wilfully blind eyes can be made to see, and wilfully unrighteous hearts can be made to practise righteousness.