John Chrysostom
Catena Aurea · Johannesevangelium 17
I have given them thy word; and the world hath hated them, because they are not of the world, even as I am not of the world. I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil. They are not of the world, even as I am not of the world. Sanctify them through thy truth; thy word is truth. As thou hast sent me into the world, even so have I also sent them into the world. And for their sakes I sanctify myself, that they also might be sanctified through the truth.
(Hom. lxxxii) Or thus: For their sakes I sanctify Myself, i. e. I offer Myself as a sacrifice to Thee; for all sacrifices, and things that are offered to God, are called holy. And whereas this sanctification was of old in figure, (a sheep being the sacrifice,) but now in truth, He adds, That they also might be sanctified through the truth; i. e. For I make them too an oblation to Thee; either meaning that He who was offered up was their head, or that they would be offered up too: as the Apostle saith, Present your bodies a living sacrifice, holy. (Rom. 12:1)