"Though it Be a Cross"
In sacrifice and offering you have not delighted,
but you have given me an open ear [Heb: “my ears you have dug”].
Burnt offering and sin offering
you have not required.
Then I said, “Behold, I have come;
in the scroll of the book it is written of me:
I delight to do your will, O God…”—Psalm 40:5-8
Slaves in Israel's economy served for seven years and were emancipated (Exodus 21:1). There was one exception: A slave might wish to remain as a servant in the house because he loved his master. In which case an ear was pierced as a sign of his or her fealty:
"If it happens that he says to you, ‘I will not go away from you,’ because he loves you and your house, since he prospers with you, then you shall take an awl and thrust it through his ear to the door, and he shall be your servant forever. Also to your female servant you shall do likewise.(Deuteronomy 15:16).
This may be the historical background of that difficult Hebrew phrase, "My ears you have dug."
The New Testament puts the words of this psalm in Jesus' mouth when He “came into the world,” to express his willingness to accept His Father's will (Hebrews 10:5-10). On this occasion, His Father’s will was the cross.
Can I take delight in God’s will “e'en though it be a cross that raise'th me”? ”The readiness is all," Hamlet said. Grace will do the rest.
 Some commentators disagree with this interpretation in that "dug" is not the normal Hebrew word for "pierced" and, in historic practice, only one ear was pierced. The Greek version (the Septuagint), the version quoted by the author of Hebrews, does not translate the phrase, but offers a paraphrase: "A body you have prepared for me," a body in which Jesus rendered complete obedience. The meaning of the passage, “I delight to do your will,” is the same, however, no matter how you translate verse 5.