Vv. 12, 13, are woven out of other psalms. 12 _a_, "Be not far from me," is found in xxii. 11, 19; xxxv. 22; xxxviii. 21, etc. "Haste to my help" is found in xxxviii. 22; xl. 13 (lxx. 1). For ver. 13 compare xxxv. 4, 26; xl. 14 (lxx. 2). With this, as a sort of refrain, the first part of the psalm ends.
The second part goes over substantially the same ground, but with lighter heart. The confidence of deliverance is more vivid, and it, as well as the vow of praise following thereon, bulk larger. The singer has thinned away his anxieties by speaking them to God, and has by the same process solidified his faith. Aged eyes should see God, the helper, more clearly when earth begins to look grey and dim. The forward look of such finds little to stay it on this side of heaven. As there seems less and less to hope for here, there should be more and more there. Youth is the time for buoyant anticipation, according to the world's notions, but age may have far brighter lights ahead than youth had leisure to see. "I will hope always" becomes sublime from aged lips, which are so often shaped to say, "I have nothing left to hope for now."
This psalmist's words may well be a pattern for old men, who need fear no failure of buoyancy, nor any collapse of gladness, if they will fix their thoughts where this singer did his. Other subjects of thought and speech will pall and run dry; but he whose theme is God's righteousness and the salvation that flows from it will never lack materials for animating meditation and grateful praise. "I know not the numbers thereof." It is something to have fast hold of an inexhaustible subject. It will keep an old man young.
The psalmist recognises his task, which is also his joy, to declare God's wondrous works, and prays for God's help till he has discharged it. The consciousness of a vocation to speak to later generations inspires him, and assures him that he is immortal till his work is done. His anticipations have been fulfilled beyond his knowledge. His words will last as long as the world. But men with narrower spheres may be animated by the same consciousness, and they who have rightly understood the purpose of God's mercies to themselves will, like the psalmist, recognise in their own participation in His salvation an imperative command to make it known, and an assurance that nothing shall by any means harm them till they have fulfilled their witnessing. A many-wintered saint should be a convincing witness for God.
Ver. 20, with its sudden transition to the plural, may simply show that the singer passes out from individual contemplation to the consciousness of the multitude of fellow-sufferers and fellow-participants in God's mercy. Such transition is natural; for the most private passages of a good man's communion with God are swift to bring up the thought of others like-minded and similarly blessed. "Suddenly there was with the angel a multitude of the heavenly host, praising." Every solo swells into a chorus. Again the song returns to "my" and "me," the confidence of the single soul being reinvigorated by the thought of sharers in blessing.
So all ends with the certainty of, and the vow of praise for, deliverances already realised in faith, though not in fact. But the imitative character of the psalm is maintained even in this last triumphant vow; for ver. 24 _a_ is almost identical with xxxv. 28; and _b_, as has been already pointed out, is copied from several other psalms. But imitative words are none the less sincere; and new thankfulness may be run into old moulds without detriment to its acceptableness to God and preciousness to men.