“Now I tell you before it come, that, when it is come to pass, ye may believe that I am he.”
John 13:19 — Greek Interlinear
Church Fathers on John 13:19
Our Lord, mindful of His promise to Peter that he should know the meaning of His act, you shall know here after, now begins to teach him: So after He had washed their feet, and had taken His garments, and was sat down again, He said to them, Know you what I have done to you?
Know you, is either interrogative, to show the greatness of the act, or imperative, to rouse their minds.
Mystically, when at our redemption we were changed by the shedding of His blood, He took again His garments, rising from the grave the third day, and clothed in the same body now immortal, ascended into heaven, and sits on the right hand of the Father, from whence He shall come to judge the world.