To the present writer it does not appear that the understanding and enjoyment of this grand psalm depend so much on success in dating it as is supposed. It may be post-exilic. Whoever fused its reminiscences of ancient triumph into such a glowing outburst of exultant faith, his vision of the throned God and his conviction that ancient facts reveal eternal truths remain for all generations as an encouragement of trust and a prophecy of God's universal dominion. The main division at ver. 18 parts the psalm into two equal halves, which are again easily subdivided into strophes. The first strophe (vv. 1-6) may be regarded as introductory to the chief theme of the first half--namely, the triumphant march of the conquering God to His sanctuary. It consists of invocation to Him to arise, and of summons to His people to prepare His way and to meet Him with ringing gladness. The ground of both invocation and summons is laid in an expansion of the meaning of His name as Helper of the helpless, Deliverer of the captive, righteous, and plentifully rewarding the proud doer. The invocation echoes the Mosaic prayer "when the ark set forward" (Numb. x. 35), with the alteration of the tense of the verb from a simple imperative into a precative future, and of "Jehovah" into God. This is the first of the quotations characteristic of the psalm, which is penetrated throughout with the idea that the deeds of the past are revelations of permanent relations and activities. The ancient history glows with present life. Whatever God has done He is doing still. No age of the Church needs to look back wistfully to any former, and say, "Where be all His wondrous works which our fathers have told us of?" The twofold conditions of God's intervention are, as this strophe teaches, Israel's cry to Him to arise, and expectant diligence in preparing His way. The invocation, which is half of Israel's means of insuring His coming, being a quotation, the summons to perform the other half is naturally regarded by the defenders of the post-exilic authorship as borrowed from Isaiah II. (_e.g._, xl. 3, lvii. 14, lxii. 10), while the supporters of an earlier date regard the psalm as the primary passage from which the prophet has drawn.