This late word, absent from the LXX, is used in Heb 7:24 of the priestly office of Jesus (ἀπαράβατον ἔχει τὴν ἱερωσύνην), which, unlike that of the Levites, does not expire with the death of the priest, but is imperishable since Jesus himself “continues for ever.” The occasionally suggested act. meaning “not to be transferred (to another)” (see J. Schneider, TDNT V, 724f.) is possible on the basis of the context, but cannot be otherwise attested. But v. 25, in particular, speaks for the translation “imperishable.” (Exegetical Dictionary of the New Testament, volume 1, eds. Horst Balz and Gerhard Schneider [Edinburgh: T&T Clark, 1990], 116)
For more on Heb 7:24 and απαραβατος, alongside other pertinent texts and issues, see my book:
