Simon bar Jonah, from the weekly audience:
Jesus did not usually change the names of his disciples”, in fact, “He never gave a new name to any of his disciples. However he did so with Simon, and that name, translated in Greek as Petros, would crop up several times in the Gospels and would end up by replacing his original name. This fact takes on particular significance when one recalls that in the Old Testament, changing a name was usually a prelude to entrusting one with a mission (cfr Jn 17:5; 32:28ff). In fact, the intention of Christ to attribute special importance to Peter within the Apostolic College emerges in many instances: in Capernaum, the Teacher went to lodge in Peter’s house (Mk 1:29); when the crowd flocked to the banks of the lake of Gennesaret, Jesus chose Peter’s boat from the two moored there (Lk 5:3); when in particular circumstances, Jesus took three disciples to accompany him, only Peter is always recalled as the first of the group: the same happened in the resurrection of the daughter of Jairus (cfr Mk 5:37; Lk 8:51); in the Transfiguration (cfr Mk 9:2; Mt 17:1; Lk 9:28), during the agony in the Garden of Gethsemane (cfr Mk 14:33; Mt 16:37). And again: it was Peter who was approached by the tax collectors at the Temple and the Teacher paid for himself and for Peter alone (cfr Mt 17: 24-27); it was Peter whose feet He washed first at the Last Supper (cfr Jn 13:6) and it was only for him that He prayed so that his faith would not fail and that he may in turn strengthen his brothers (cfr Lk 22: 30-31)”.
“Peter himself is, after all, aware of his unique position: it is he who often, in the name also of the rest, speaks out, asking for an explanation for some difficult parable (Mt 15:15) or the exact meaning of a precept (Mt 18:21) or the formal promise of reward (Mt 19:27).”