John 6:71

He spoke of Judas the son of Simon Iscariot , for he , one of the Twelve , was going to betray him .

(He meant Judas, the son of Simon Iscariot, who, though one of the Twelve, was later to betray him.)

He spake of Judas Iscariot the son of Simon : for he it was that should betray him, being one of the twelve. John 5 Books John 7