Ezekiel 21:14
Thou therefore, son of man, prophesy, and smite thine hands together, and let the sword be doubled the third time, the sword of the slain: it is the sword of the great men that are slain, which entereth into their privy chambers. Thou therefore, son of man, prophesy, and smite thine hands together, and let the sword be doubled the third time, the sword of the slain: it is the sword of the great men that are slain, which entereth into their privy chambers.
Ezekiel 21 belongs to the prophet's account of the steps that led Israel into exile, tracing how the nation was brought into trouble and dispersion. That trouble came through idolatry and Sabbath desecration, which are set forth in the chapter as the causes of their downfall. Within that setting the command to prophesy and smite the hands together, and to let the sword be doubled the third time, points to the destruction of the kingdom of Judah and a change in human dominion.
The doubling of the sword the third time means that three further overturnings of ruling power were still to take place. The first overturning would be by Medo-Persia, the second by Grecia, and the third by Rome. After those three overturnings Christ would come, and the kingdom would be His.