Ver. 20 may belong to the individual voice, but is perhaps better taken as the answer from within the Temple, of the priests or Levites who guarded the closed doors, and who now proclaim what must be the character of those who would tread the sacred courts. The gate (not as in ver. 19, _gates_) belongs to Jehovah, and therefore access by it is permitted to none but the righteous. That is an everlasting truth. It is possible to translate, "This is the gate _to_ Jehovah"--_i.e._, by which one comes to His presence; and that rendering would bring out still more emphatically the necessity of the condition laid down: "Without holiness no man shall see the Lord."
The condition is supposed to be met; for in ver. 21 the individual voice again breaks into thanksgiving, for being allowed once more to stand in the house of Jehovah. "Thou hast answered me": the psalmist had already sung that Jah had answered him (ver. 5). "And art become my salvation": he had already hailed Jehovah as having become such (ver. 14). God's deliverance is not complete till full communion with Him is enjoyed. Dwelling in His house is the crown of all His blessings. We are set free from enemies, from sins and fears and struggles, that we may abide for ever with Him, and only then do we realise the full sweetness of His redeeming hand, when we stand in His presence and commune evermore with Him.
Vv. 22, 23, 24, probably belong to the priestly chorus. They set forth the great truth made manifest by restored Israel's presence in the rebuilt Temple. The metaphor is suggested by the incidents connected with the rebuilding. The "stone" is obviously Israel, weak, contemptible, but now once more laid as the very foundation stone of God's house in the world. The broad truth taught by its history is that God lays as the basis of His building--_i.e._, uses for the execution of His purposes--that which the wisdom of man despises and tosses aside. There had been abundant faint-heartedness among even the restored exiles. The nations around had scoffed at these "feeble Jews," and the scoffs had not been without echoes in Israel itself. Chiefly, the men of position and influence, who ought to have strengthened drooping courage, had been infected with the tendency to rate low the nation's power, and to think that their enterprise was destined to disaster. But now the Temple is built, and the worshippers stand in it. What does that teach but that all has been God's doing? So wonderful is it, so far beyond expectation, that the very objects of such marvellous intervention are amazed to find themselves where they stand. So rooted is our tendency to unbelief that, when God does what He has sworn to do, we are apt to be astonished with a wonder which reveals the greatness of our past incredulity. No man who trusts God ought to be surprised at God's answers to trust.
The general truth contained here is that of Paul's great saying, "God hath chosen the weak things of the world that He might put to shame the things that are strong." It is the constant law, not because God chooses unfit instruments, but because the world's estimates of fitness are false, and the qualities which it admires are irrelevant with regard to His designs, while the requisite qualities are of another sort altogether. Therefore, it is a law which finds its highest exemplification in _the_ foundation for God's true temple, other than which can no man lay. "Israel is not only a figure of Christ--there is an organic unity between Him and them. Whatever, therefore, is true of Israel in a lower sense is true in its highest sense of Christ. If Israel is the rejected stone made the head of the corner, this is far truer of Him who was indeed rejected of men, but chosen of God and precious, the corner stone of the one great living temple of the redeemed" (Perowne).