Exegesis:

hoti ‘that’ is recitative, introducing direct speech.

hosa (cf. 3.8) ‘all things,’ ‘as many things (as).’

gegraptai ep’ autōn (cf. previous verse) ‘it is written concerning him.’

Translation:

The impersonal use of they in the expression they did to him is difficult to render in many languages. In general one can translate they by some such expression as ‘the people,’ but in this instance obviously the opposition to John the Baptist was not prompted by the populace in general but by certain persons. This will require ‘some people’ or ‘certain persons.’

As it is written of him is generally equivalent to a paratactically combined clause, ‘that is just the way the Scriptures speak of him’ or ‘that is the way it is told about him in the Writings.’

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 .