Chapter — Wouters, Manual of Moral Theology
Chapter I. On the Existence of the Sacrament of Matrimony
Matrimony is a true sacrament. This proposition is of faith, for example from the Council of Trent: "If anyone says that matrimony is not truly and properly one of the seven sacraments of the evangelical law, instituted by Christ the Lord, but invented by men in the Church, and that it does not confer grace, let him be anathema."1
Note 1. The time of the institution of this sacrament by Christ is uncertain. Some judge that it was instituted at the wedding at Cana;2 others, when Christ established the indissolubility of Matrimony;3 finally others, after the Resurrection, at the time when the Lord conversed with his disciples, speaking of the kingdom of God.4
Note 2. Matrimony in the Old Law not only was not an efficacious sign of grace, but does not seem to be counted among the sacraments of the Old Law, that is, among the signs of grace then existing. "But matrimony," says St. Thomas, "was indeed in the Old Law insofar as it was for the office of nature, but not insofar as it is the sacrament of the conjunction of Christ and the Church, which had not yet been made; hence also in the Old Law a bill of repudiation was given, which is contrary to the nature of a sacrament" (I-II, q. 102, a. 5, ad 3).
2 John 2.
3 Matthew 19:4.
4 Acts 1:3.