"I, the true murderer, felt the never-dying worm alive in my bosom, which allowed of no hope or consolation"

   Frankenstein here references a passage from Chapter 9 of the Gospel of Mark, in which Christ describes the wicked undergoing eternal torment in Hell "Where their worm dieth not, and the fire is not quenched".  The novel's re-wording is identical to that found in 18th-century minister Matthew Henry's six-volume commentary, which fittingly interprets the immortal 'worm' as representing the sinner's "remorse of conscience and keen self-reflection".

Online edition of the 'Authorized King James Bible', (originally published 1611)

Online edition of Matthew Henry's 'Concise Commentary on the Whole Bible', (originally published 1706)