Take great stones - This discourse seems to have been delivered about a year after the destruction of Jerusalem. They pretended that they dared not stay in Judea for fear of the Chaldeans. The prophet here assures them that Nebuchadnezzar shall come to Egypt, extend his conquests in that kingdom, and place his tent over the very place where these stones were laid up, and destroy them. How these prophecies were fulfilled, see at the end of Jeremiah 44:30; (note).
Brickkiln - Possibly, a pavement of brick. Jeremiah was to take a few large stones, such, nevertheless, as he could carry in his hand, and build with them, in the propylaea before the royal palace, something that would serve to represent the dais upon which the seat of kings was usually placed. By hiding them in the clay is meant plastering them over with mortar.