John Gill Commentary Jeremiah 27:14

"And hearken not unto the words of the prophets that speak unto you, saying, Ye shall not serve the king of Babylon; for they prophesy a lie unto you." — Jeremiah 27:14 (ASV)

Therefore do not listen to the words of the prophets The false prophets, as the Targum; such bad kings always had about them, to whom they listened, and this often proved of bad consequence to them:

that speak to you, saying as follows:

you shall not serve the king of Babylon you ought not to do it, but cast off his yoke; If you do not willingly submit to this, he will never be able to force you.

for they prophesy a lie to you and therefore should not be listened to, particularly when they promise safety from the king of Babylon.