Jeremiah 7:21-23
21 The Lord Almighty, Israel's God, says this to Judah's people:
‘Eat the meat from your burnt offerings, as well as your other sacrifices. It makes no difference. You are not offering them to me! 22 Remember this: I brought your ancestors safely out of Egypt. Then I gave them my commands. Those commands were not only about burnt offerings and sacrifices. 23 I also told them, “Obey me. Then I will be your God, and you will be my people. You must live in the way that I have commanded you. If you do that, you will enjoy your lives.”
7:21 God's Law said that people should not eat the meat from burnt offerings. See Leviticus 1:6-9. God is telling them that they are not obeying his Law at all. So the rules about sacrifices were no longer important. 