He is giving PETER the keys to the kingdom of heaven.
And with them the AUTHORITY to bind and lose on earth!
The point here is that Christ is conferring this authority on Peter, assuring him that his decisions will be guided by the Holy Spirit.
So that when man is uncertain as to the meaning of Scripture, they will be able to look to Peter for the correct understanding.
Kinda hard that now what with Peter not being present any longer.