The closing verses of this psalm reappear with slight changes as an independent whole in Psalm lxx. The question arises whether that is a fragment or this a conglomerate. Modern opinion inclines to the latter alternative, and points in support to the obvious change of tone in the second part. But that change does not coincide with the supposed line of junction, since Psalm lxx. begins with our ver. 13, and the change begins with ver. 12. Cheyne and others are therefore obliged to suppose that ver. 12 is the work of a third poet or compiler, who effected a junction thereby. The cumbrousness of the hypothesis of fusion is plain, and its necessity is not apparent, for it is resorted to in order to explain how a psalm which keeps so lofty a level of confidence at first should drop to such keen consciousness of innumerable evils and such faint-heartedness. But surely such resurrection of apparently dead fears is not uncommon in devout, sensitive souls. They live beneath April skies, not unbroken blue. However many the wonderful works which God has done and however full of thankfulness the singer's heart, his deliverance is not complete. The contrast in the two parts of the psalm is true to facts and to the varying aspects of feeling and of faith. Though the latter half gives greater prominence to encompassing evils, they appear but for a moment; and the prayer for deliverance which they force from the psalmist is as triumphant in faith as were the thanksgivings of the former part. In both the ground tone is that of victorious grasp of God's help, which in the one is regarded in its mighty past acts, and in the other is implored and trusted in for present and future needs. The change of tone is not such as to demand the hypothesis of fusion. The unity is further supported by verbal links between the parts: _e.g._, the innumerable evils of ver. 12 pathetically correspond to the innumerable mercies of ver. 5, and the same word for "surpass" occurs in both verses; "be pleased" in ver. 13 echoes "Thy pleasure" (will, A.V.) in ver. 8; "cares" or _thinks_ (A.V.) in ver. 17 is the verb from which the noun rendered _purposes_ (thoughts, A.V.) in ver. 5 is derived.