The second principal division begins with ver. 10, and is a prayer for purity, followed by vows of glad service. The prayer is contained in three verses (10-12), of which the first implores complete renewal of nature, the second beseeches that there may be no break between the suppliant and God, and the third asks for the joy and willingness to serve which would flow from the granting of the desires preceding. In each verse the second clause has "spirit" for its leading word, and the middle one of the three asks for "_Thy_ holy spirit." The petitions themselves, and the order in which they occur, are deeply significant, and deserve much more elucidation than can be given here. The same profound consciousness of inward corruption which spoke in the former part of the psalm shapes the prayer for renewal. Nothing less than a new creation will make this man's heart "clean." His past has taught him that. The word employed is always used of God's creative act; and the psalmist feels that nothing less than the power which brooded over the face of primeval chaos, and evolved thence an ordered world, can deal with the confused ruin within himself. What he felt that he must have is what prophets promised (Jer. xxiv. 7; Ezek. xxxvi. 26) and Christ has brought--a new creation, in which, while personality remains unaffected, and the components of character continue as before, a real new life is bestowed, which stamps new directions on affections, gives new aims, impulses, convictions, casts out inveterate evils, and gradually changes "all but the basis of the soul." A desire for pardon which does not unfold into such longing for deliverance from the misery of the old self is not the offspring of genuine penitence, but only of base fear.
"A steadfast spirit" is needful in order to keep a cleansed heart clean; and, on the other hand, when, by cleanness of heart, a man is freed from the perturbations of rebellious desires and the weakening influences of sin, his spirit will be steadfast. The two characteristics sustain each other. Consciousness of corruption dictated the former desire; penitent recognition of weakness and fluctuation inspires the latter. It may be observed, too, that the triad of petitions having reference to "spirit" has for its central one a prayer for God's Spirit, and that the other two may be regarded as dependent on that. Where God's Spirit dwells, the human spirit in which it abides will be firm with uncreated strength. His energy, being infused into a tremulous, changeful humanity, will make it stable. If we are to stand fast, we must be stayed on God.
The group of petitions in ver. 11 is negative. It deprecates a possible tragic separation from God, and that under two aspects. "Part me not from Thee; part not Thyself from me." The former prayer, "Cast me not out from Thy presence," is by some explained according to the analogy of other instances of the occurrence of the phrase, where it means expulsion from the land of Israel; and is claimed, thus interpreted, as a clear indication that the psalmist speaks in the name of the nation. But however certainly the expression is thus used elsewhere, it cannot, without introducing an alien thought, be so interpreted in its present connection, imbedded in petitions of the most spiritual and individual character: much rather, the psalmist is recoiling from what he knows only too well to be the consequence of an unclean heart--separation from God, whether in the sense of exclusion from the sanctuary, or in the profounder sense, which is not too deep for such a psalm, of conscious loss of the light of God's face. He dreads being, Cain-like, shut out from that presence which is life; and he knows that, unless his previous prayer for a clean heart is answered, that dreary solitude of great darkness must be his lot. The sister petition, "Take not Thy holy spirit from me," contemplates the union between God and him from the other side. He regards himself as possessing that Divine spirit; for he knows that, notwithstanding his sin, God has not left him, else he would not have these movements of godly sorrow and yearnings for purity. There is no reason to commit the anachronism of supposing that the psalmist had any knowledge of New Testament teaching of a personal Divine Spirit. But if we may suppose that he is David, this prayer has special force. That anointing which designated and fitted him for kingly office symbolised the gift of a Divine influence accompanying a Divine call. If we further remember how it had fared with his predecessor, from whom, because of impenitence, "the Spirit of the Lord departed, and an evil spirit from the Lord troubled him," we understand how Saul's successor, trembling as he remembers his fate, prays with peculiar emphasis, "Take not Thy Holy Spirit from me."