In the fourth year of Zedekiah's reign, a false prophet named Hananiah speaks to Jeremiah in the temple in front of the priests and all the people.
He says that God has broken Babylon's yoke, and will return God's holy vessels to the temple and release the ex-King Coniah and the other exiles.
Jeremiah says that it would be great if God did those things. But he says that the real prophets in the past had predicted war, famine, and disease.
If a prophet who predicts peace somehow managed to be right—well, then it would really be impressive, and you'd know God sent that prophet.
Hananiah then symbolically breaks the yoke from around Jeremiah's neck, the one that God had ordered him to wear.
He says this is how God will break the Babylonians' yoke from Judah. He thinks he's clever.
Jeremiah goes away, but the word of God comes to him. It says to tell Hananiah that he's broken off the wooden yoke only to have it replaced with an iron yoke. Judah and the other nations will most definitely fall to Nebuchadnezzar.
Jeremiah goes to Hananiah and tells him that he's made the people believe in a lie. As punishment, God's planning on killing him within the year.