Mark 9:48
Mark 9:4848where ‘their worm never dies, and the fire is never quenched.’
JW commentary reads as borrowing from , where the imagery describes corpses on the rubbish heap outside Jerusalem after the final battle. Because the corpses are dead, the "maggot" and "fire" describe ongoing destruction of inanimate matter, not ongoing conscious suffering. The verse is read as figurative confirmation of the JW doctrine of annihilation — the maggot keeps consuming and the fire keeps burning until nothing is left.
Jesus's source — — describes the corpses of those "who have rebelled against me" being a perpetual sight of judgement. The image is meant as a warning, and the metaphor is pressed by Jesus into ongoing reality: maggot does not die, fire is not extinguished. If destruction were complete annihilation, the maggot would have nothing to feed on and would die; the fire would burn out. Jesus deliberately uses the language of perpetual ongoing process to describe the state of those under divine judgement. Pair with ("they have no rest day or night") and ("they will be tormented day and night forever and ever") for the consistent apocalyptic picture of conscious post-mortem punishment.
The NWT renders skōlēx as "maggot" rather than the standard "worm." The choice nudges the imagery toward decay-of-corpses rather than toward the more theologically loaded "worm" that (the source text) and standard translations preserve. The NWT also renders the verb sbennytai as "is not put out" rather than "is not quenched." Both substitutions are small but tilt the verse away from the active-fire / undying-worm imagery that supports a conscious-punishment reading and toward a more passive imagery of dead matter being consumed. Combined with the Gehenna transliteration in v. 43, the cluster supports the JW annihilationist reading by softening the unending qualities Jesus's source text emphasises.