{Simon he surnamed Peter} (epeth(886b)en onoma t(9369) Sim(936e)i
Petron). The Greek idiom seems awkward, but it is not. Peter is
in apposition with _name_ or onoma (accusative). This surname
Jesus gave in addition (epeth(886b)en) to Simon (dative case). Here
then is a direct reference to what is told in  Joh 1:42  when
Jesus met Simon for the first time. Mark here reflects Peter's
own words. Luke ( Lu 6:14 ) simply says "Whom he also surnamed
Peter." See  Mt 16:18  for the full explanation of the name
Peter, a Rock, Cephas.