Jeremiah 51:12

Set up the standard upon the walls of Babylon, raising a flag or emblem to indicate a particular point of attack, make the watch strong, so that the siege would be equally effective along the whole line, set up the watchmen, against the city, so that there would be no loophole of escape for the besieged, prepare the ambushes, in order to take the first opportunity of entering into the city; for the Lord hath both devised and done that which He spake against the inhabitants of Babylon, that is, what He had determined upon He would most certainly carry out against the wicked city.