Roman Catechism 16.31

Chapter 16 — Part II: The Sacraments — Baptism

Section 31. Administration of Baptism — What has been said on the matter and form, which are required for the essence of the Sacrament, will be found sufficient for the instruction of the faithful; but as in the administration of the Sacrament the legitimate manner of ablution should also be observed, pastors should teach the doctrine of this-point also.