In verses Matthew 18:8 and Matthew 18:9 we have one of the dualities or doublets in Matthew (Matthew 5:29-30). Jesus repeated his pungent sayings many times. Instead of εις γεενναν (Matthew 5:29) we have εις το πυρ το αιωνιον and at the end of verse Matthew 18:9 του πυρος is added to την γεενναν. This is the first use in Matthew of αιωνιος. We have it again in Matthew 19:16; Matthew 19:29 with ζοη, in Matthew 25:41 with πυρ, in Matthew 25:46 with κολασιν and ζοην. The word means ageless, without beginning or end as of God (Romans 16:26), without beginning as in Romans 16:25, without end as here and often. The effort to make it mean "αεονιαν" fire will make it mean "αεονιαν" life also. If the punishment is limited, ipso facto the life is shortened. In verse Matthew 18:9 also μονοφθαλμον occurs. It is an Ionic compound in Herodotus that is condemned by the Atticists, but it is revived in the vernacular Koine. Literally one-eyed. Here only and Mark 9:47 in the New Testament.