DECREE
OF THE COUNCIL OF TRENT.
That the faithful may approach the Sacraments with greater
reverence and devotion, the Holy Synod commands all Bishops not
only to explain, in a manner accommodated to the capacity of the
receivers, the nature and use of the Sacraments, when they are to
be administered by themselves; but also to see that every Pastor
piously and prudently do the same, in the vernacular language,
should it be necessary and convenient. This exposition is to accord
with a form to be prescribed by the Holy Synod for the administration of all the Sacraments, in a Catechism, which bishops will take care to have faithfully translated into the vernacular language, and expounded to the people by all pastors.
Conc. Trid. Sess. 24. de Reform, c. 7