The Lord has no delight in various sacrifices, like burnt offerings and sin offerings. Those sacrifices can however be attempts to make things right with God. So, the Lord will not reject all sacrifices. Especially in Leviticus we can find many regulations pertaining to sacrifices and the liturgy. Thus, sacrifices do belong to the relationship that God’s people have with the Lord.
The author mentions something very important: you have opened my ears. It means something like dug out my ears.
Think of plugged up ears which need to be unplugged. The meaning behind this is that the Lord has taught me to be obedient. You listen well to the law of God, and you are doing your best to live according to it—in word and deed. And now the Lord is saying: That has more meaning than busying yourself with sacrifices.
The unplugging or digging out makes us think of the bond a slave has with his master. With an awl, a hole was made in the slave’s ear, with which his availability was sealed. You can read about this in Exodus 21:6 and in Deuteronomy 15:17. There is, however, a clear difference between a hole made in the ear and the opening of the ear passage. What they have in common is the obedience.
From 1 Samuel 15:22, where Saul sins, we learn that obedience means more than offering sacrifices: “Has the Lord as great delight in burnt offerings and sacrifices, as in obeying the voice of the Lord? Behold, to obey is better than sacrifice, and to listen than the fat of rams.” Samuel also warns Saul against rebellion, idolatry, etc. and concludes with you have rejected the word of the Lord.
The prophet Amos also speaks sternly to the people, in Amos 5:21–22: I hate, I despise your feasts, and I take no delight in your solemn assemblies. Even though you offer me your burnt offerings and grain offerings, I will not accept them; and the peace offerings of your fattened animals, I will not look upon them.
And he adds the threat of the exile to come (Amos 5:27).
The reason can be found in Amos 5:11–12 among other places: because you trample on the poor and you exact taxes of grain from him…you who afflict the righteous, who take a bribe, and turn aside the needy in the gate.
Clearly, there is distressing social injustice, while sacrifices are still being offered. Isaiah also speaks to the people about the multitude of sacrifices that the Lord does not delight in (see Isaiah 1:11 and onward; Psalm 50:8, Psalm 50:14, and Psalm 51:19). So, it is not about the bringing of sacrifices, but about sacrificing yourself to the Lord and to those around you.
6 In sacrifice and offering you have not delighted, but you have given me an open ear. Burnt offering and sin offering you have not required.