Part — Wouters, Manual of Moral Theology
Part I. On the Existence of the Sacrament of Confirmation
111.
Confirmation is a true sacrament of the New Law. This is of faith from these words of the Council of Trent: "If anyone says that the Confirmation of the baptized is an idle ceremony and not rather a true and proper sacrament... let him be anathema."1
It is doubtful at what time Christ instituted Confirmation. According to some, at the Last Supper; according to others, after the resurrection and before the ascension, namely while He was speaking with the Apostles about the kingdom of God and completing the mysteries of salvation;2 according to others, on the day of Pentecost.
1 Session 7, On Confirmation, canon 1.
2 Acts 1:3.