It is a reasonable conjecture that the Hallelujah at the end of Psalm civ., where it is superfluous, properly belongs to this psalm, which would then be assimilated to Psalm cvi., which is obviously a companion psalm. Both are retrospective and didactic; but Psalm cv. deals entirely with God's unfailing faithfulness to Israel, while Psalm cvi. sets forth the sad contrast presented by Israel's continual faithlessness to God. Each theme is made more impressive by being pursued separately, and then set over against the other. The long series of God's mercies massed together here confronts the dark uniformity of Israel's unworthy requital of them there. Half of the sky is pure blue and radiant sunshine; half is piled with unbroken clouds. Nothing drives home the consciousness of sin so surely as contemplation of God's loving acts. Probably this psalm, like others of similar contents, is of late date. The habit of historical retrospect for religious purposes is likely to belong to times remote from the events recorded. Vv. 1-15 are found in 1 Chron. xvi. as part of the hymn at David's setting up of the Ark on Zion. But that hymn is unmistakably a compilation from extant psalms, and cannot be taken as deciding the Davidic authorship of the psalm.
Vv. 1-6 are a ringing summons to extol and contemplate God's great deeds for Israel. They are full of exultation, and, in their reiterated short clauses, are like the joyful cries of a herald bringing good tidings to Zion. There is a beautiful progress of thought in these verses. They begin with the call to thank and praise Jehovah and to proclaim His doings among the people. That recognition of Israel's office as the world's evangelist does not require the supposition that the nation was dispersed in captivity, but simply shows that the singer understood the reason for the long series of mercies heaped on it. It is significant that God's "deeds" are Israel's message to the world. By such deeds His "name" is spoken. What God has done is the best revelation of what God is. His messengers are not to speak their own thoughts about Him, but to tell the story of His acts and let these speak for Him. Revelation is not a set of propositions, but a history of Divine facts. The foundation of audible praise and proclamation is contemplation. Therefore the exhortation in ver. 2_b_ follows, which means not merely "speak," but may be translated, as in margin of the Revised Version, "meditate," and is probably best rendered so as to combine both ideas, "musingly speak." Let not the words be mere words, but feel the great deeds which you proclaim. In like manner, ver. 3 calls upon the heralds to "glory" for themselves in the name of Jehovah, and to make efforts to possess Him more fully and to rejoice in finding Him. Aspiration after clearer and closer knowledge and experience of God should ever underlie glad pealing forth of His name. If it does not, eloquent tongues will fall silent, and Israel's proclamation will be cold and powerless. To seek Jehovah is to find His strength investing our feebleness. To turn our faces towards His in devout desire is to have our faces made bright by reflected light. And one chief way of seeking Jehovah is the remembrance of His merciful wonders of old, "He hath made His wonderful works to be remembered" (Psalm cxi. 4), and His design in them is that men should have solid basis for their hopes, and be thereby encouraged to seek Him, as well as be taught what He is. Thus the psalmist reaches his main theme, which is to build a memorial of these deeds for an everlasting possession. The "wonders" referred to in ver. 5 are chiefly those wrought in Egypt, as the subsequent verses show.
Ver. 6 contains, in the names given to Israel, the reason for their obeying the preceding summonses. Their hereditary relation to God gives them the material, and imposes on them the obligation and the honour, of being "secretaries of God's praise." In ver. 6_a_ "His servant" may be intended to designate the nation, as it often does in Isa. xl.-lxvi. "His chosen ones" in ver. 6_b_ would then be an exact parallel; but the recurrence of the expression in ver. 42, with the individual reference, makes that reference more probable here.