What is the significance of Jeremiah 19:5?

The Lord says that Israel has “gone on building the high places of Baal to burn their children in the fire as burnt offerings to Baal, which I did not command or decree, nor did it enter my mind.”

Here, as elsewhere, (7:31, 32:35), the Lord expresses disappointment, if not shock, over Israel’s idolatry. The most straightforward reading of the text suggests the Lord is admitting that it never occurred to him his people would actually behave in this deplorable manner. However we understand the phrase “nor did it enter my mind,” it would at the very least seem to preclude the possibility that the Israelites’ idolatrous behavior was eternally known in God’s mind. If God was eternally certain that the Israelites would do exactly what they did, as the classical understanding of foreknowledge requires, it is difficult to see how God could be speaking truthfully when he says it did not enter his mind that they would do this.

If we accept that the future is partly open, however, we can understand the Lord to be honestly expressing his dismay at the Israelites behavior. Of course the Lord would have known about the remote possibility of this behavior, for he knows all of reality, and whatever comes to pass was eternally possible to come to pass. But the remoteness of the possibility grounds the authenticity of the Lord’s declaration: he never thought they’d actually sink this low! And so far as I can see, such a declaration is utterly unintelligible if God was eternally certain the Israelites would sink precisely as low as they did and behave exactly as they did.