Origen

(t. xxxii. 8.) Or thus: I speak not of you all, does not refer to, Happy are ye if ye do them. For of Judas, or any other person, it may be said, Happy is he if he do them. The words refer to the sentence above, The servant is not greater than his lord, neither He that is sent greater than He that sent Him. For Judas, being a servant of sin, was not a servant of the Divine Word; nor an Apostle, when the devil had entered into him. Our Lord knew those who were His, and did not know who were not His, and therefore says, not, I know all present, but, I know whom I have chosen, i. e. I know My Elect.