Exegesis:

ponēra (as an adjective only here and in v. 22; cf. the noun ponēriai in v. 22) ‘wicked,’ ‘evil.’

Translation:

The translation of this verse, as regards the form of things come from … must, of course, follow the pattern of the first part of verse 21. Accordingly, one may need to translate this as ‘because of what is within a person he does all these bad deeds.’

For defile see 7.15.

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 .