All the while He is speaking, Jesus knows Peters heart and that he will indeed feed His sheep and that he will suffer death because of it and the manner of his physical death. Yet He reveals all of this to Peter couched in the "if/then": Do you love me? Feed my sheep.
He saith to him again the second time, Simon, [son] of Jonas, lovest thou me? He saith unto him, Yea, Lord; thou knowest that I love thee. He saith unto him, Feed my sheep.
He saith unto him the third time, Simon, [son] of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep.
Verily, verily, I say unto thee, When thou wast young, thou girdedst thyself, and walkedst whither thou wouldest: but when thou shalt be old, thou shalt stretch forth thy hands, and another shall gird thee, and carry [thee] whither thou wouldest not. This spake he, signifying by what death he should glorify God. And when he had spoken this, he saith unto him, Follow me. John 21:15-19
So we see both predestination and free will in Jesus words to Peter.
He knows what Peter will do and what shall happen to him but reveals by the "if/then" that Peter has the freedom of movement to love Jesus or not - and thus to feed His sheep (in the power of the words of God) - or not.
To God be the glory!
Since "feed my sheep" is a metaphorical reference.. The object of the metaphor must be gained.. How does a shepherd feed sheep?.. Obviously a shepherd does not feed sheep he takes them to where they can feed themselves.. a pasture.. A shepherd leads sheep to a bountiful pasture where they feed themselves.. Not pre digested stuff from the shepherds mouth.. The metaphor is rich and deep.. and exposes many errors.. Conversations with a real shepherd is a worthy task.. Feeding sheep in a holding pen(sheep pen) is much different than feeding them in a pasture.. Ps 23.. A mental task of considering sheep in a holding pen and sheep in a pasture would be a good meditation for any metaphorical shepherd..
Then his freedom is faux freedom. It's a charade. He is led to believe that he has freedom but God didn't tell him the whole truththat his choices have been "preordained." He is under the impression that he is free to choose, and yet he is not. He is deceived.
And Christian God does not deceive. Those who say that Peter was made to believe he was free to choose are saying God decieved, indeed lied to Peter. Just as those who claim that Christ did not die on the Cross are saying that Christ decieved the world into believing he did die on the cross.
That's Santa Klaus theology, with a twist.