The prophet Jeremiah lived during the time when the Babylonians invaded Judah (beginning in 597 BCE) and then captured Jerusalem in 586 BCE, razing the temple and sending many of its residents captive to the Babylonian empire—a period conveniently referred to as the Babylonian exile.
Jeremiah was not a popular figure. He found himself butting heads with the people and the leaders over the events of the day, one issue, in particular, I’d like to mention here.
The Babylonians were practically knocking on Jerusalem’s door, and it was assumed by many that their sacrifices would appease God and keep the Babylonians off their back. That didn’t happen, of course, and it probably didn’t help that some of those sacrifices were apparently of their own children (7:31).
At any rate, Jeremiah really leans into this idea that offering sacrifices would keep them safe, and in 7:21-23, Jeremiah says something we can’t pass over (and he’s a little sarcastic, too):
Thus says the LORD of hosts, the God of Israel: Add your burnt offerings to your sacrifices, and eat the flesh. For in the day that I brought your ancestors out of the land of Egypt I did not speak to them or command them concerning burnt offerings and sacrifices. But this command I gave them, “Obey my voice, and I will be your God, and you shall be my people; and walk only in the way that I command you, so that it may be well with you.”
Whatever those commands were that the Israelites coming out of Egypt were supposed to obey, they apparently did not include commands about sacrifices, since, as we read, God did not command them—which is hard to accept if you’ve ever slogged through the many laws about sacrifices in Leviticus.
The note to this passage in the Jewish Study Bible explains this passage by saying that obedience to God is more ancient than sacrifices.
In Exodus, at Mount Sinai, the Israelites received all sorts of laws covering many social and religious issues. And yes, offering sacrifices was a given (see Exodus 20:22-26, for example). Jeremiah is not saying that sacrifices were unheard of back in the days of the Exodus. Every ancient culture had sacrifice baked into their religious systems, and the Israelites were no different. We see the idea already in the Cain and Abel story.
But for commands “concerning burnt offering and sacrifices” you need to go to Leviticus. The more elaborate and detailed commands about sacrifice are to be found there, and that is what Jeremiah says was not part of the legislation given at Mount Sinai.
And this is one of the reasons why many scholars for the last 200 years or so have argued that the laws in Leviticus are not from Moses’s time but generated by a priestly class from a later time—late enough for these laws not to be on Jeremiah’s radar screen.
Bottom line: Jeremiah says that God never said what the Law of Moses said he said. That is because the Pentateuch that we can pick up and read anytime we want do did not yet exist in Jeremiah’s day. And that’s at least something worth thinking about.