God commanded Jeremiah to perform a symbolic act: hiding large stones in the brick platform at the entrance to Pharaoh's palace. Commentators explain this was a living prophecy. The stones represented the foundation of the throne that God would establish for King Nebuchadnezzar of Babylon, right on Egypt's doorstep. This visual demonstration was meant to shock the stubborn exiles into realizing that God's judgment was certain and inescapable.