Matthew Poole and continuators on Jeremiah 36:21

21 So the king sent Jehudi to set the roll, And he took it out of Elishama the scribes chamber, And Jehudi read it in the ears of the king, and in the ears of all the princes which stood beside the king .

It appeareth by v. 14. that this Iehudi was a Messenger commonly imployed by the king, and Councel, him the King sends to fetch the Roll (before called a book) then he imployeth him to read it.