Isaiah 66:24
And they shall go forth, and look upon the carcases of the men that have transgressed against me: for their worm shall not die, neither shall their fire be quenched; and they shall be an abhorring unto all flesh. And they shall go forth, and look upon the carcases of the men that have transgressed against me: for their worm shall not die, neither shall their fire be quenched; and they shall be an abhorring unto all flesh.
The verse shows the final destruction of those who have rebelled and transgressed against God, who are consumed by fire with soul and body destroyed. Their remains are left an abhorrence. The worm is the worm of life, which does not die while any part remains for it to prey upon. The undying worm and unquenched fire mean that the work of punishment continues only as long as anything remains to consume or to burn. The wicked suffer for differing lengths of time according to their deeds, but are ultimately consumed rather than kept alive forever. This includes Satan and all the wicked, who suffer everlasting death with no resurrection.
The verse describes the sure consequence of sin for those who persist in sin and refuse Christ, forgiveness, and grace; they do not escape its results. The unrepentant sinner realizes too late that sin is transgression of God's law that cut the soul off from God, and is destroyed under God's abiding wrath. When punished for transgression, those portrayed experience remorse, despair, and hatred.