This term appears in Psalm 39:1, where the psalmist resolves: 'I will keep a muzzle on my mouth while the wicked are in my presence.' The word refers to a device that prevents animals from biting or eating, here applied metaphorically to human speech. The psalmist commits to self-imposed silence, binding his own mouth to prevent sinful or erring words when confronted by the wicked. The muzzle imagery is stronger than mere 'guard'—it suggests forcible restraint of speech, recognizing the mouth's tendency toward unbridled expression.