Revelation 9:19; Power is in their Mouths

Revelation 9:19 For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt. 

The writer relates that the power to kill human beings resides in both the front and the back of the horses, that is, in their mouths and tails.

Revelation 9:10 And they had tails like unto scorpions, and there were stings in their tails: and their power wasto hurt men five months. 

Their mouths figuratively spew forth fire, smoke, and sulfur, while their tails resemble snakes that bite. John does not say that the riders of these horses kill human beings, but that the horses have that power. The text, then, is highly symbolic, so that we have to think in terms of demonic forces that are given authority to kill God’s adversaries. With both heads and tails, these demons inflict untold harm. [Kistemaker, S. J., & Hendriksen, W. (1953–2001). Exposition of the Book of Revelation (Vol. 20, pp. 299–300). Grand Rapids: Baker Book House]

Having likened the horses’ heads to savage lions, John notes that their tails are like deadly, venomous serpents and have heads, and with them they do harm. The horse’s tails were not actual serpents, because the horses were not actual horses. The horse was anointed with war force, the lion with vicious, deadly power, the serpent with deadly venom. These images describe the supernatural deadliness of this demon force in terms that are commonly understood in the natural realm. Unlike the scorpion stings inflicted during the previous demonic assault (9:5), the snakebites inflicted by this host will be fatal. [MacArthur, J. F., Jr. (1999). Revelation 1–11 (p. 272). Chicago: Moody Press]

Revelation 2:16 Repent; or else I will come unto thee quickly, and will fight against them with the sword of my mouth.

Amen.