King James Version
He spake of Judas Iscariot the son of Simon: for he it was that should betray him, being one of the twelve.English Standard Version
He spoke of Judas the son of Simon Iscariot, for he, one of the Twelve, was going to betray him.New International Version
(He meant Judas, the son of Simon Iscariot, who, though one of the Twelve, was later to betray him.)