The conversation as recorded shows Peter making no response, but Jesus brings it up again. So when Jesus asks Peter for a second time, “Do you care for me?” – we put ourselves in Peter's place and expect the Lord to add a new request. And with that expectation, we wouldn't stretch hard to imagine at least some part of Peter was probably hoping for a tougher assignment, or at least more than just food duty. Whatever Peter expected, he responds again with an emphatic, “I phileo you.” But the friend of the King gets the same task assignment again. And according to the record of this conversation, Peter goes quiet again.
Unfortunately we can only speculate on how Peter felt about Jesus' instructions at this point. Some will assume Peter knew Jesus meant preaching. I seriously doubt that. But I think the overall text gives us a picture that Peter's silence means he wasn't real sure what Jesus was talking about, yet. And I personally suspect Peter wasn't real thrilled with an assignment that sounded so normal. Whatever he's thinking, here is the man who confidently proclaims "You know I'm your man", falling silent as soon as he gets the details.
Mind-reading aside, Jesus definitely picks up on the difference between Peter's general enthusiasm up front and and his lack of reply when things got specific. Of course, they both konw this moment is about restoring Peter to a position of service to his King. But it's becoming clear that Peter may not understand what type of service Jesus is actually hoping for.
So the Lord decides, with his third question, to challenge the whole "friend" concept, as it currently exists in Peter's mind.
(To be concluded…)