In the third part (vv. 7, 8), the psalmist comes back to his own needs, and takes to his heart the calming assurance born of his experience, that he bears a charmed life. He but speaks the confidence which should strengthen every heart that rests on God. Such an one may be girdled about by troubles, but he will have an inner circle traced round him, within which no evil can venture. He may walk in the valley of the shadow of death unfearing, for God will hold his soul in life. Foes may pour out floods of enmity and wrath, but one strong hand will be stretched out against (or _over_) the wild deluge, and will draw the trustful soul out of its rush on to the safe shore. So was the psalmist assured; so may and should those be who have yet greater wonders for which to thank Jehovah.
That last prayer of the psalm blends very beautifully confidence and petition. Its central clause is the basis of both the confidence in its first, and the petition in its last, clause. Because Jehovah's loving-kindness endures for ever, every man on whom His shaping Spirit has begun to work, or His grace in any form to bestow its gifts, may be sure that no exhaustion or change of these is possible. God is not as the foolish tower-builder, who began and was not able to finish. He never stops till He has completed His work; and nothing short of the entire conformity of a soul to His likeness and the filling of it with Himself can be the termination of His loving purpose, or of His achieving grace. Therefore the psalmist "found it in his heart to pray" that God would not abandon the works of His own hands. That prayer appeals to His faithfulness and to His honour. It sets forth the obligations under which God comes by what He has done. It is a prayer which goes straight to His heart; and they who offer it receive the old answer, "I will not leave thee till I have done unto thee that which I have spoken to thee of."