“And after the sop Satan entered into him. Then said Jesus unto him, That thou doest, do quickly.”
King James Version (KJV)
13:27 What thou doest, do quickly - This is not a permission, much less a command. It is only as if he had said, If thou art determined to do it, why dost thou delay? Hereby showing Judas, that he could not be hid, and expressing his own readiness to suffer.
Joh 13:27 Satan entered into him. He gave himself up at once to Satan's purpose. What thou doest, do quickly. Judas understood what these words meant, but no one else.