Vv. 7 and 8 are occupied with the response to God's requirements thus manifested by His gift of capacity to hear His voice. "Then said I." As soon as he had learned the meaning of his ears he found the right use of his tongue. The thankful heart was moved to swift acceptance of the known will of God. The clearest recognition of His requirements may coexist with resistance to them, and needs the impulse of loving contemplation of God's unnumbered wonders to vivify it into glad service. "Behold, I am come," is the language of a servant entering his master's presence in obedience to his call. In ver. 7 the second clause interrupts just as in ver. 6. There the interruption spoke of the organ of receiving Divine messages as to duty; here it speaks of the messages themselves: "In the roll of the book is my duty prescribed for me." The promise implied in giving ears is fulfilled by giving a permanent written law. This man, having ears to hear, has heard, and has not only heard, but welcomed into the inmost recesses of his heart and will, the declared will of God. The word rendered "delight" in ver. 8 is the same as is rendered "desire" in ver. 6 (A.V.); and that rendered by the A.V. and R.V. in ver. 8 "will" is properly "good pleasure." Thus God's delight and man's coincide. Thankful love assimilates the creature's will with the Divine, and so changes tastes and impulses that desire and duty are fused into one. The prescriptions of the book become the delight of the heart. An inward voice directs. "Love, and do what Thou wilt"; for a will determined by love cannot but choose to please its Beloved. Liberty consists in freely willing and victoriously doing what we ought, and such liberty belongs to hearts whose supreme delight is to please the God whose numberless wonders have won their love and made their thanksgivings poor. The law written in the heart was the ideal even when a law was written on tables of stone. It was the prophetic promise for the Messianic age. It is fulfilled in the Christian life in the measure of its genuineness. Unless the heart delights in the law, acts of obedience count for very little. The quotation of vv. 7, 8, in Heb. x. 5-7, is mainly from the LXX., which has the remarkable rendering of ver. 6 _b_, "A body hast Thou prepared for me." Probably this is meant as paraphrase rather than as translation; and it does represent substantially the idea of the original, since the body is the instrument for fulfilling, just as the ear is the organ for apprehending, the uttered will of God. The value of the psalm for the writer of Hebrews does not depend on that clause, but on the whole representation which it gives of the ideal of the perfectly righteous servant's true worship, as involving the setting aside of sacrifice and the decisive pre-eminence of willing obedience. That ideal is fulfilled in Jesus, and really pointed onwards to Him. This use of the quotation does not imply the directly Messianic character of the psalm.