Sacrifice and offering thou didst not desire; mine ears hast thou opened: burnt offering and sin offering hast thou not required.
The second half of the first part, Psalms 40:6-10. The petitioner testifies that he doeth God's will from the heart, not merely in external forms.
Sacrifice and offering thou didst not desire. The Hebrew zebach (H2077) and minchaah (H4503) are, respectively, the bloody and the unbloody offerings. The natural man vainly tries to compound for obedience with sacrifice. Obedience of heart and act, the moral duty, is the main thing, and is the end for which the positive ordinance was instituted. Where the sacrifice was the expression of faith and obedience, there it was accepted; otherwise it was valueless before God (cf. Psalms 50:5; Psalms 50:8-14; Psalms 51:16-17; Hosea 6:6; 1 Samuel 15:22; Jeremiah 7:22-24). In regard to expiation, what God desired was not the blood of bulls and goats, but the sacrifice which alone could put away sin-namely, that of "Christ, who through the eternal Spirit offered Himself without spot to God" (Hebrews 9:13-14; Hebrews 10:4-10.
Mine ears hast thou opened - literally, 'thou hast digged.' The sense is, thou hast made me willingly obedient; as in the passage of Jeremiah just quoted, and in Isaiah 50:5, where also, as here, Messiah is the speaker - "The Lord God hath opened mine ear, and I was not rebellious." As the way in which he testified his obedience was by the assumption of a human body, the Septuagint version, which Hebrews 10:5-10 gives inspired sanction to, translate, 'a body thou hast prepared me'-literally, 'fitted for me' х kateertisoo (G2675) moi (G3427)]. See my note there. The apostle brings out the deep sense latent in the psalm. The ear is the member of the body which symbolizes obedience. Hence, the boring of a bond-servant's ear was the token whereby he signified his desire still to remain his master's servant, when he might be free (Exodus 21:6; Deuteronomy 15:17). So the Divine Word testified His desire to become the Father's servant by voluntarily assuming a human body, in order to offer the one only expiatory sacrifice which the Father desired, and of which all other 'sacrifices' were but shadowy types, having in themselves nothing acceptable to God. God opened Messiah's internal ear - i:e., framed Him as the sinless man, willing to offer such a wonderful proof of obedience.
Burnt offering and sin offering - here joined, because they had this in common, that neither were partaken of by the offerer.