John Gill Commentary Jeremiah 20:6

"And thou, Pashhur, and all that dwell in thy house shall go into captivity; and thou shalt come to Babylon, and there thou shalt die, and there shalt thou be buried, thou, and all thy friends, to whom thou hast prophesied falsely." — Jeremiah 20:6 (ASV)

And you, Pashur, and all that dwell in your house, shall go
into captivity. Particularly he and his family should not escape, whoever else did: and you shall come to Babylon; being brought there, though sorely against his will: and there you shall die, and shall be buried there; even in a defiled land, as all other countries were reckoned by the Jews; and to be buried in such a land, Kimchi observes, was a curse; and so it is here threatened as such: you, and all your friends; that is, such as should escape the sword (Jeremiah 20:4); to whom you have prophesied lies.

This shows the cause of all this threatened destruction to him and his friends: not only because he had so ill used Jeremiah, a true prophet of the Lord, but because he was a false prophet, and his friends had listened to his lies, and disbelieved those prophecies that came from the Lord himself.