This sentence is omitted in one ms. (Paris, 1824), but probably only through the repetition of the word “baptism.”  On the laws of the Church against the repetition of Baptism, and concerning the re-baptism of heretics, see Tertull. de Baptismo, c. xv:  Apost. Const. xv.:  Bingham, xii. 5:  Hefele, Councils, Lib. I. c. 2:  Dictionary Christian Antiq. I. p. 167 a.