Exegesis:

kata with the genitive meaning ‘against’ (3.6; 11.25; 14.55, 56, 57).

huper (14.24) with the genitive ‘for,’ ‘in behalf of.’

Translation:

Against us … for us would seem to be simple enough, but prepositions such as ‘against’ and ‘for’ do not exist in some languages, and the entire concept must be shifted into verb constructions, e.g. ‘the man who does not fight against us is on our side,’ ‘the man who does not work against us is helping us,’ ‘for he goes with us, who is not against us’ (Batak Toba), or ‘he who does not look mean at us is ours’ (Kekchi).

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 .