John Calvin Commentary John 17:10

"and all things that are mine are thine, and thine are mine: and I am glorified in them." — John 17:10 (ASV)

And all things that are mine are thine. The object of the former clause is to show that the Father will assuredly listen to him. “I do not,” says he, “plead with you for any but those whom you acknowledge to be yours, for I have nothing separated from you, and therefore I will not meet with a refusal.” In the second clause, and thine are mine, he shows that he has good reason for caring about the elect; for they are his in consequence of their being his Father’s. All these things are spoken for the confirmation of our faith.

We must not seek salvation anywhere else than in Christ. But we will not be satisfied with having Christ, if we do not know that we possess God in him. We must therefore believe that there is such a unity between the Father and the Son as makes it impossible that they will have anything separate from each other.

And I am glorified in them. This is connected with the second clause of the verse, and thine are mine; for it follows that it is reasonable that he, for his part, should promote their salvation. This is a most excellent testimony for confirming our faith: that Christ will never cease to care for our salvation, since he is glorified in us.