Today is the Octave Day of Christmas -- the Eighth Day of Christmas -- which now marks the Solemnity of the Blessed Virgin Mary, the Mother of God. It used to commemorate the Feast of the Circumcision of Our Lord and bore the title In Circumcisione Domini et Octav Nativitatis. It represented Jesus, the "Giver of the Law," as consenting to submit to the Law of Moses, and also as spilling His blood for the first time for the sake of mankind. Thus, it demonstrated not only the obedience of Jesus, but forshadowed His Crucifixion.
The eighth day following His birth, Jesus was presented in the Temple and circumcised according to the Law of Moses. On this occasion, He was given the name Jesus, which the Archangel Gabriel had announced to the Virgin Mary. Circumcision was the Old Covenant proto-type of baptism in the New Covenant. In fulfilling the Old Testament Law, Jesus also replaced it with Baptism in His Church as was proclaimed by the Apostle Paul: "For neither does circumcision mean anything, nor does uncircumcision, but only a new creation" (Galatians 6:15).
Note that the Mother of God was never eclipsed in the traditional commemoration of the Circumcision of Our Lord. As John J. Tierney wrote in his article on "Feast of the Circumcision" in the Catholic Encyclopedia exactly a hundred years ago in 1908:It is to be noted also that the Blessed Virgin Mary was not forgotten in the festivities of the holy season, and the Mass in her honour was sometimes said on this day. Today, also, while in both Missal and Breviary the feast bears the title In Circumcisione Domini et Octav Nativitatis, the prayers have special reference to the Blessed Virgin, and in the Office, the responses and antiphons set forth her privileges and extol her wonderful prerogatives. The psalms for Vespers are those appointed for her feasts, and the antiphons and hymn of Lauds keep her constantly in view.Note also, however, that the Circumcision of Our Lord has all but disappeared from discourse surrounding the Solemnity of the Blessed Virgin Mary, the Mother of God. We ought to try and remedy that.