Albert Barnes Commentary Jeremiah 26:9

"Why hast thou prophesied in the name of Jehovah, saying, This house shall be like Shiloh, and this city shall be desolate, without inhabitant? And all the people were gathered unto Jeremiah in the house of Jehovah." — Jeremiah 26:9 (ASV)

The charge against Jeremiah was that of prophesying falsely, for which the penalty was death (Deuteronomy 18:20). They assumed that it was absolutely impossible that Jerusalem ever could become like Shiloh.

Against Jeremiah — to Jeremiah. They regularly constituted themselves a congregation to take part in his trial.