John Gill Commentary Jeremiah 25:28

"And it shall be, if they refuse to take the cup at thy hand to drink, then shalt thou say unto them, Thus saith Jehovah of hosts: Ye shall surely drink." — Jeremiah 25:28 (ASV)

And it shall be, if they refuse to take the cup at your hand to drink To give credit to the prophecies of ruin and destruction delivered by the prophet, but say, these things shall not be:

then shall you say to them, thus says the Lord of hosts, you shall certainly drink; or those judgments shall certainly be inflicted; there will be no possibility of escaping, whether they were believed or not; or how unwilling soever they were to believe the denunciations of them, or to have them come upon them; yet assuredly so it would be; for thus says the Lord of hosts, who is omnipotent, and does what he pleases in the armies of heaven, and among the inhabitants of the earth, over whom he has a despotic power and government,