Both. Certainly it is directed to and only for Israel, but it does give us some better understanding of the God we call on. He is not always full of grace. Judgment is also part of his nature. There is an end to his patients.
Jeremiah was being told by God to not pray for the Judeans of his day for he is about to send them into captivity. Especially the leaders. God is tearing down the house (throne) of David because of the idolatry of the people. Some will return after Seventy years. The house of Israel had been gone for over a hundred years and have not yet returned.
30Reprobate silver shall men call them, because the LORD hath rejected them.
Like many today they thought they were okay....the false prophets of their day told them peace peace....when there was no peace...like Joel Osteen and the word of faith heretics in our day.
They did not think they need to repent.....they thought they could just place their faith in a false message......rather than the elect remnant whom God promised he would preserve....with a God given faith.