to the nature and will of God (cf. ἀλήθεια, Eph 4:21). חכמה, wisdom which is most intimately acquainted with (eindringlich weiss) such nature and life and the way to attain it. God delights in and desires truth בטּחות. The Beth of this word is not a radical letter here as it is in Job 12:6, but the preposition. The reins utpote adipe obducti, here and in Job 38:36, according to the Targum, Jerome, and Parchon, are called טחות (Psychol. S. 269; tr. p. 317). Truth in the reins (cf. Psa 40:9, God's law in visceribus meis) is an upright nature in man's deepest inward parts; and in fact, since the reins are accounted as the seat of the tenderest feelings, in man's inmost experience and perception, in his most secret life both of conscience and of mind (Psa 16:7). In the parallel member סתם denotes the hidden inward part of man. Out of the confession, that according to the will of God truth ought to dwell and rule in man even in his reins, comes the wish, that God would impart to him (i.e., teach him and make his own), - who, as being born and conceived in sin, is commended to God's mercy, - that wisdom in the hidden part of his mind which is the way to such truth.
Verses 7-9
The possession of all possessions, however, most needed by him, the foundation of all other possessions, is the assurance of the forgiveness of his sins. The second futures in Psa 51:9 are consequents of the first, which are used as optatives. Psa 51:9 recalls to mind the sprinkling of the leper, and of one unclean by reason of his contact with a dead body, by means of the bunch of hyssop (Lev. 14, Num. 19), ), the βοτάνη καθαρτική (Bähr, Symbol. ii. 503); and Psa 51:9 recalls the washings which, according to priestly directions, the unclean person in all cases of uncleanness had to undergo. Purification and washing which the Law enjoins, are regarded in connection with the idea implied in them, and with a setting aside of their symbolic and carnal outward side, inasmuch as the performance of both acts, which in other cases takes place through priestly mediation, is here supplicated directly from God Himself. Manifestly בּאזוב (not כבאזוב) is intended to be understood in a spiritual sense. It is a spiritual medium of purification without the medium itself being stated. The New Testament believer confesses, with Petrarch in the second of his seven penitential Psalms: omnes
