say that רוּח הקּדשׁ (as in Isa 63:16), πνεῦμα ἁγιωσύνης = ἅγιον, is here the Spirit of grace in distinction from the Spirit of office. If Jahve should reject David as He rejected Saul, this would be the extreme manifestation of anger (2Ki 24:20) towards him as king and as a man at the same time. The Holy Spirit is none other than that which came upon him by means of the anointing, 1Sa 16:13. This Spirit, by sin, he has grieved and forfeited. Hence he prays God to show favour rather than execute His right, and not to take this His Holy Spirit from him.
Verses 12-13
In connection with רוּח נדיבה, the old expositors thought of נדיב, a noble, a prince, and נדיבה, nobility, high rank, Job 30:15, lxx πνεύματι ἡγεμονικῷ (spiritu principali) στήριξόν με, - the word has, however, without any doubt, its ethical sense in this passage, Isa 32:8, cf. נדבה, Ps. 54:8; and the relation of the two words רוח נדיבה is not to be taken as adjectival, but genitival, since the poet has just used רוח in the same personal sense in Psa 51:12. Nor are they to be taken as a nominative of the subject, but - what corresponds more closely to the connection of the prayer - according to Gen 27:37, as a second accusative of the object: with a spirit of willingness, of willing, noble impulse towards that which is good, support me; i.e., imparting this spirit to me, uphold me constantly in that which is good. What is meant is not the Holy Spirit, but the human spirit made free from the dominion of sin by the Holy Spirit, to which good has become an inward, as it were instinctive, necessity. Thus assured of his justification and fortified in new obedience, David will teach transgressors the ways of God, and sinners shall be converted to Him, viz., by means of the testimony concerning God's order of mercy which he is able to bear as the result of his own rich experience.
Verses 14-17
The third part now begins with a doubly urgent prayer. The invocation of God by the name Elohim is here made more urgent by the addition of אלהי תשׁוּעתי; inasmuch as the prayers for justification and for renewing blend together in the “deliver me.” David does not seek to lessen his guilt; he calls it in דּמים by its right name, - a word which signifies blood violently shed, and then also a deed of blood and blood-guiltiness (Psa 9:13; Psa 106:38, and frequently). We have
