A.T. Robertson Commentary 2 Corinthians 6:13

"Now for a recompense in like kind (I speak as unto [my] children), be ye also enlarged." — 2 Corinthians 6:13 (ASV)

Now for a recompense in like kind (την δε αυτην αντιμισθιαν). No example of this expressive word outside of this passage and Ro 1:27 and later Christian writers. Paul may have found it in use in the Koine vernacular or he may have coined it from αντιμισθος, remunerating (paying back). There is no verb here to explain the accusative which may be the accusative of general reference or the object of a verb not expressed.

Be ye also enlarged (πλατυνθητε κα υμεις). As I have been (verse 11). First aorist passive imperative of πλατυνω.