The phrase “to gnash the teeth” could describe a literal action or a figurative one functioning as an idiomatic phrase. The Greek noun brugmos could be translated as “gnashing, grinding, shattering the teeth.” The image may have originated in the experience of facing a wild animal that gnashes its teeth before launching an attack. It may also describe what happens to our teeth when we experience intense cold. In any case, it’s not just a bodily expression but an emotional one. The phrase is found seven times in the Gospels to describe the condition of the wicked in the final judgment. It’s also found in the Old Testament. I will highlight three important meanings.
1. Manifestation of Anger
In the Old Testament the expression “to gnash the teeth” is used metaphorically to express the attitude of the wicked toward the righteous. The wicked are described as an aggressive animal, driven by irrational anger and ready to attack: “They gnashed at me with their teeth” (Ps. 35:16). This type of attack is premeditated: “The wicked plots against the just, and gnashes at him with his teeth” (literally, “he gnashes his teeth against me,” Ps. 37:12; see Acts 7:54). After the fall of Jerusalem, Jeremiah describes the attitude of the enemy, saying, “All your enemies have opened their mouth against you; they hiss and gnash their teeth” (Lam. 2:16). Job applies the metaphor to God: “He tears me in His wrath, and hates me; He gnashes at me with His teeth” (Job 16:9). The phrase is used in those passages during confrontations between the righteous and the wicked, specifically when the wicked has the upper hand. But the phrase is also applied to the wicked when the righteous is victorious: “He [the wicked] will gnash his teeth and melt away” (Ps. 112:10), namely, he will be in pain and sorrow.
2. Manifestation of Despair and Remorse
In the Gospels the meaning of the phrase “to gnash the teeth” is determined by its context. In all its uses the wicked are facing God’s eternal judgment against them. The full phrase used is “there will be weeping/ wailing and gnashing of teeth” (Matt. 8:12; 13:42, 50; 22:13; 24:51; 25:30). Weeping points to sorrow for the loss the wicked now experience, and the gnashing of teeth expresses their deep regret and despair. They now realize what they have done and their indescribable eternal loss: “There will be weeping and gnashing of teeth, when you see Abraham and Isaac and Jacob and all the prophets in the kingdom of God, and yourselves thrust out. They will come from the east and the west, from the north and the south, and sit down in the kingdom of God” (Luke 13:28, 29; cf. Matt. 13:42, 43). They lost the eternal fellowship of the righteous with the Lord in the kingdom of heaven.
3. Manifestation of Eternal Separation
The phrase “weeping and the gnashing of teeth” is also used to express the anguish of the wicked after realizing that they are eternally separated from God (cf. Acts 20:36-38). In the context of each passage the key point is that the wicked are separated from the righteous and cast out into outer darkness—the absence of God (Matt. 8:12; 22:13; 25:30)—or into the fire of eternal death (Matt. 13:42, 50), or simply thrust out (Luke 13:28) of God’s kingdom. At that moment they will be angered at themselves for not joining the One who went into the darkness of separation from God for them (Luke 22:53; Matt. 27:45, 46).
