Exegesis:

parrēsia (only here in Mark) ‘freely,’ ‘boldly,’ ‘confidently’ (Moulton & Michigan); ‘frankly,’ ‘plainly,’ ‘concealing nothing.’

proslabomenos (only here in Mark) ‘taking aside.’

epitiman (cf. 1.25) ‘to reprove,’ ‘to rebuke,’ ‘to censure.’ In this verse and the next one, this meaning seems preferable to Translator’s New Testament ‘check.’

Translation:

Rebuke in this passage is not easy to translate. In some languages the term used means ‘to scold,’ which is relatively close to the original. On the other hand, some languages require a form of direct discourse, ‘he said, This should not be.’ Peter was not specifically commanding Jesus to quit talking in this way, so much as condemning his thinking and planning such a course of action as would lead to this result. If this meaning can be conveyed by a rendering such as ‘said to him, Don’t talk this way,’ a relatively close equivalent of the Greek will have been found.

Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on the Gospel of Mark. (UBS Handbook Series). New York: UBS, 1961. For this and other handbooks for translators see here .