What does Hebrews 10:5 mean?
A recurring theme in the book of Hebrews is the use of Old Testament quotations. The writer is making it very clear that the message of the New Testament is not a rejection of the Old, or a claim that Judaism was wrong. Instead, the point of the old covenant was to foreshadow the new covenant. The physical objects and rituals were meant to explain mankind's need for a single, perfect sacrifice. The repeated rituals, the use of human priests, and even the construction of the temple were all meant to demonstrate this truth (Hebrews 9:8–10). To support this idea, the writer has shown how God, in His word, has promised this new covenant, which is fulfilled completely in Jesus Christ.The point of this new covenant is not a repetitive, temporary sacrifice. It is not about delaying judgment or dealing with ceremony. Instead, the new covenant is meant to be a permanent, personal cleansing from sin (Hebrews 8:7–13).
In verses 5, 6, and 7 the author quotes from Psalm 40:6–8, once again appealing to the Old Testament to prove this was, in fact, God's plan all along. This quotation is interesting because the writer of Hebrews quotes from the Septuagint, a Greek translation of the Hebrew Scriptures. For this reason, Hebrews 10:5 and Psalm 40:6 are often phrased differently, in English, in the same translation. The ESV, for instance, translates Psalm 40:6 as "you have given me an open ear." The KJV makes a similar choice.
The literal Hebrew phrasing in Psalm 40:6 refers to God "digging ears" for the Psalmist. This seems to be a Hebrew idiom which implies God forming ears which allowed a person to receptively hear His Word. This also implies the idea that God is the one who has fashioned the body of the speaker. The Septuagint translator, as quoted by the writer of Hebrews, seems to have emphasized the latter aspect of the idiom. The point referenced from the Old Testament, then, is that God has "digged ears," or "dug ears," or "given open ears," or "created the body" of the person speaking.