For the Son of man goeth ( ὑπάγει)—goeth, departeth from this mortal scene: the reference is, of course, to his death—even as it is written of him; as, for example, in Psalms 22:1-31 and Isaiah 41:1-29 It was foreordained by God that he was to suffer as a victim for the sins of the whole world.
But this predestined purpose of God did not make the guilt any the less of those who brought the Savior to his cross. Good were it for that man if he had not been born. The Greek is καλὸν ἦν αὐτῷ εἰ οὐκ ἐγεννήθη ὁ ἄνθρωπος ἐκεῖνος: literally, good were it for him, if that man had not been born.
Better not to have lived at all than to have lived and died ill. Existence is no blessing, but a curse, to him who consciously and wilfully defeats the purpose of his existence. St. Matthew (Matthew 26:25) here introduces Judas as asking the question, "Is it I, Rabbi?"
And our Lord answers him affirmatively, "Thou hast said." This was probably said in a low voice. Had it been said so as to be heard by others, such as Peter and John, they might have risen at once to inflict summary vengeance upon the apostate traitor.