However, compare Jesus’ words with the final verse of Isaiah’s prophecy.b Is it not apparent that Jesus was alluding to the text in Isaiah chapter 66? The prophet there apparently refers to going out “of Jerusalem to the surrounding Hinnom Valley (Gehenna), where human sacrifice was once practiced (Jer 7:31) and which eventually became the city’s refuse heap.” (The Jerome Biblical Commentary) The symbolism at Isaiah 66:24 clearly is not that of people being tortured; it speaks of carcasses. What it refers to as not dying is worms​—not live humans or immortal souls. What, then, is the import of Jesus’ words?

Note the comment on Mark 9:48 in the Catholic work El evangelio de Marcos. Análisis lingüístico y comentario exegético, Volume II: “[The] phrase is taken from Isaiah (66,24). There the prophet shows the two ways corpses were usually destroyed: putrefaction and incineration . . . The juxtaposition in the text of maggots and fire reinforces the idea of destruction. . . . Both destructive forces are described as permanent (‘is not quenched, does not die’): there is simply no way to escape them. In this image, the only survivors are the maggot and the fire​—not man—​and they both annihilate anything that falls within their power. Hence, this is not a description of everlasting torment, but one of total destruction which, as it prevents resurrection from occurring, is tantamount to final death. [Fire] is, then, a symbol of annihilation.”