Revelation 16:13

And I saw coming out of the mouth of the dragon, and out of the mouth of the beast, and out of the mouth of the false prophet, three unclean spirits, as it were frogs:

Out of the mouth of the dragon ... the beast ... the false prophet ... Ah! Here are the "kings of the east" mentioned above. Their purpose in crossing the boundary will quickly appear.

Three unclean spirits, as it were frogs ... "Their evil influence is shown under the figure of frogs, because it was by producing frogs that the magicians deceived Pharaoh (Exodus 8:7).[37] The next verse tells us more about these frogs. "To say that they come out of the mouth of the dragon, the beast and the false prophet is to say that their words are like plagues, unclean, empty futilities and allies of the powers of darkness."[38] The dragon, the beast, and the false prophet were accurately identified by Summers as "the devil, godless government and false religion."[39] Lange called these frogs "the modern nightingales who announce the new springtime of mankind."[40] From the dirtiness and slimey nature of the frogs, we may conclude that they are the devil's propaganda agents, making a lot of noise like frogs, but being in themselves small, weak, dirty, and despicable.

[37] J. R. Dummelow. Commentary on the Holy Bible (New York: The Macmillan Company, 1937), p. 1086.

[38] William Barclay, op. cit., p. 130.

[39] Ray Summers, op. cit., p. 189.

[40] Lange as quoted by Lenski, op. cit., p. 477.