And Baruch said to them: With his mouth he pronounced all these words as if he were reading to me: and I wrote in a volume with ink.

And Baruch saith to them, 'From his mouth, he pronounceth unto me all these words, and I am writing on the book with ink.'

Then Baruch, answering, said, He said all these things to me by word of mouth, and I put them down with ink in the book.

Then Baruch answered them, 'He pronounced all these words to me with his mouth, and I wrote them with ink on the scroll.'

Then Baruch said to them: "He was speaking with his mouth, as if reading to me. And I wrote in a volume with ink."

Et dixit illis Baruch, Ex ore suo pronuntiavit mihi cunctos sermones istos, et ego scripsi super librum cum atramento.

He pronounced - He used to say aloud, he dictated. Baruch's office was merely mechanical. He contributed nothing but hand, pen, and ink.

Then Baruch answered them,.... At once, without any hesitation, plainly and fully:
he pronounced all these words unto me with his mouth; that is, the Prophet Jeremiah delivered by word of mouth, not the substance only of this roll, but the express words of it, and everyone of them, and that clearly and distinctly, without any hesitation, or premeditation; by which it is plain it was by the Spirit of the Lord he did it; neither matter nor words were Baruch's, but were exactly as they were delivered:
and I wrote them with ink in the book; as they saw with their eyes, and which was the manner of writing with the Jews so early; Baruch had no further concern in this matter than to provide pen, ink, and parchment, and to make use of them as he did, just as the prophet dictated and directed him.

his mouth--Baruch replies it was by the oral dictation of the prophet; Jeremiah 36:2 accords with this view, rather than with the notion that Jeremiah repeated his prophecies from manuscripts.
ink--his specification of the "ink" implies: I added nothing save the hand, pen, and ink.

He pronounced - This could not but add to the princes fear, they must needs conceive that without a special influence of God, it had been impossible, that Jeremiah should have called to mind all that he had spoken at several times in so many years.