Regarding the circumcision of Christ, let me share with you a wonderful litle word from Saint Ambrose, assigned to the Divine Office this morning. As you read this, take note of a few things: 1. the christological focus of Ambrose's reading of the Old Testament, 2. the rich imagery Ambrose employs as he develops the notion of Mary as an icon of the Church, 3. and what I find to be a subtle but significant point, namely, that Ambrose does not say that Christ opened His mother's womb (he couldn't say that, since that didn't happen) but nevertheless uses that imagery to make a point about the fruitfulness of the Church.
But since the body and mind of man remain yet infected with a proneness to sin, the circumcision of the eighth day is meant to put us in mind of that complete cleansing from sin which we shall have at the resurrection. This is doubtless to be inferred from the words : Every male that openeth the womb shall be called holy unto the Lord. That is, these words are literally true only of the delivery of the Blessed Virgin. Verily, he that opened her womb was holy, for he was altogether without spot. And we may gather that the Law hath this meaning because the Angel said almost the same words : That Holy Thing which shall be born of thee shall be called the Son of God.
Among all them that are born of women the Lord Jesus Christ stood alone in holiness. He alone, because of this immaculate birth, felt no contagion from human corruption ; it came not near him because of his heavenly majesty. Otherwise (that is, if we are to apply this passage of the Law literally) we are obliged to say that without exception every male that openeth the womb is holy ; and how then shall we explain that so many were unrighteous? Was Ahab holy? Were the false prophets holy? Were they holy on whom Elijah justly called down fire from heaven? But he to whom the sacred commandment of the Law of God is mystically directed is the Holy One of Israel. And he alone hath opened the secret womb of his holy virgin-bride the Church, filling her with a sinless fruitfulness whereby to bring forth the People of God.