Albert Barnes Commentary Jeremiah 45:1

"The word that Jeremiah the prophet spake unto Baruch the son of Neriah, when he wrote these word in a book at the mouth of Jeremiah, in the fourth year of Jehoiakim the son of Josiah, king of Judah, saying," — Jeremiah 45:1 (ASV)

These words—that is, the words of Jehoiakim’s scroll.