Albert Barnes Commentary Jeremiah 36:12

"he went down into the king`s house, into the scribe`s chamber: and, lo, all the princes were sitting there, [to wit], Elishama the scribe, and Delaiah the son of Shemaiah, and Elnathan the son of Achbor, and Gemariah the son of Shaphan, and Zedekiah the son of Hananiah, and all the princes." — Jeremiah 36:12 (ASV)

The scribe’s chamber - The chancery in which the king’s business was conducted. Probably Elishama was one of the principal scribes of the host (Jeremiah 52:25), that is, the secretary of state for war. The business which had brought together all the princes related to the Chaldaean war.