John Gill Commentary Jeremiah 36:1

"And it came to pass in the fourth year of Jehoiakim the son of Josiah, king of Judah, that this word came unto Jeremiah from Jehovah, saying," — Jeremiah 36:1 (ASV)

And it came to pass in the fourth year of Jehoiakim the son of
Josiah king of Judah
Eighteen years before the destruction of Jerusalem: [that] this word came to Jeremiah from the Lord ;
giving the following order to write in a roll all his prophecies he had hitherto delivered: saying ;
as follows: