From the Holy Gospel according to Luke
Luke 2:21In that time: when eight days were accomplished, that the child should be circumcised, his name was called Jesus, which was called by the angel, before he was conceived in the womb. And so on.
Homily by St. Bernard, Abbot (of Clairvaux)
1st on the Circumcision
Behold a mystery, great and full of wonder! The Child is circumcised, and His Name is called Jesus. Why are these two things thus mentioned together? It would seem that circumcision should rather be for the saved than for the Saviour; that the Saviour ought rather to be Circumciser than circumcised. But behold here the Mediator between God and men, how even from His childhood He joineth the things of the Highest to the things of the lowest, the things of God to the things of men. He is born of a woman, but her womb is made fruitful without the loss of the flower of her virginity. He is wrapped in swaddling-bands, but these swaddling-bands are a theme for the jubilation of angels. He is laid in a manger, but a bright star standeth in heaven over the place. So also in His circumcision, the ceremony gave proof of the reality of the Manhood which He had taken, and that Name which is above every name proclaimed the glory of His Blessed Majesty. As very son of Abraham He underwent circumcision; He assumed the Name of Jesus as very Son of God.
Why Jesus beareth not that Name as others have borne it before Him, as a vain and empty title. It is not in Him the shadow of a great Name, but the very meaning of that Name. That His Name was revealed from heaven, is attested by the Evangelist, where it is written, Which was so named of the Angel before He was conceived in the womb. After Jesus was born, men called Him Jesus, but angels called Him Jesus, before He was conceived in the womb. The One Lord is the Saviour of angels and of men; of men, since His Incarnation; of angels, from the beginning of their creation. His Name, saith the Evangelist, was called Jesus, which was so named of the Angel before He was conceived in the womb. In the mouth therefore of two or three witnesses is every word established; and that word whereof the Prophet spoke as cut short, is set forth at length in the Gospel: the Word made Flesh.
And on the Circumcision
It is no wonder that it should be at His circumcision that the Name of Jesus (which is, being interpreted, Saviour) is given to the Child Who is born unto us, for it was then that He for the first time shed that sinless Blood Which is the mean whereby He hath chosen to work out our salvation. It is no matter for the speculation of Christians why the Lord Christ was pleased to be circumcised. He was circumcised for the same reason for which He was born, and for which He suffered. Neither one nor the other was for Himself, but all for the sake of the elect. He was not born in sin; He was not circumcised to separate Him from sin; neither did He die for sins of His own, but for ours. Which was so named of the Angel before He was conceived in the womb. The Angel indeed gave Him that title of Saviour, but not for the first time. Saviour is His Name from everlasting; He hath it of His own proper nature to save. This title He hath in Himself, not by the gift of anything that He hath made, be it man or Angel.