Genesis 17:1-7,9-12, 14 LXX, especially vs. 7, "And I will establish My covenant between thee and thy seed after thee, to their generations, for an everlasting covenant, to be thy God, and the God of thy seed after thee." The Exaposteilarion of today's Feast declares: "Verily, the Creator of ages Who fulfilled the law is circumcised in the flesh as an eight-day old child, is wrapped in swaddling clothes like a man and is fed with milk, He Who is the All-Controller through His boundless might, since He is God, and the Maker of the law in flesh."
Observe the wording of declaration: "the Creator of the ages...fulfilled the law." The statements that follow concerning His circumcision, clothing as a man, and being fed milk, appear to specify ways in which He fulfills the law in concrete terms. How are we to understand these actions as fulfillment? What is filled full, put into effect, brought to an end, satisfied, converted into reality or brought to its potential?
The "laws" of the created order require infants to be fed and clothed for survival, yet the Lord Who is unbounded and is eternally free from any need for protection has chosen to take our flesh upon Himself, for He is God the Word assuming the limitations and demands of the natural law. Therefore, He was diapered and nursed. Observe that His satisfaction of the natural law is expressed in many of the icons of the Nativity for they regularly show Him being washed and cared for as well as being "wrapped...in swaddling cloths" (Lk. 2:7).
These most mundane, human actions direct us to the Apostle Paul's point: when the Lord was "found in appearance as a man, He humbled Himself," lowered Himself in every respect (Phil. 2:7). In other words, He came into the world and joined Himself to us an actual man in order to address the terrible side of being human: separation from God and our wedding to death.
Note: for mankind's salvation, God requires a perfect man to reestablish our fallen race. There must be an actual flesh-and-blood man who also is sinless. In our history, we have had many flesh-and-blood men, but in our union with Adam our race lost the potential to produce a perfect man. So to speak, "we keep turning out sinners." None of us can respond to that which God asked of Abraham: "be well-pleasing before Me, and be blameless" (Gen. 17:1 LXX). Who is blameless?
However, we know that through the action of the Holy Spirit overshadowing a pure virgin, God did produce a Man, One Who lived perfectly and blamelessly , Who by death trampled down death, and as God bestows life upon all in the tombs and upon all who are destined for the tombs.
Continuing on, let us also note that the Lord's circumcision fulfills another level of "law," which the passage in Genesis 17 illumines. Observe: God told Abraham, "I will establish My covenant between Me and thee, and I will multiply thee exceedingly.... [therefore] thy name shall no more be called Abram, but thy name shall be Abraham, for I have made thee a father of many nations" (vss. 2, 5). This covenant required that all males who were inheritors of these promises be circumcised on the eighth day after birth (vss. 9-12). Obviously, the Virgin Mary and Joseph fulfilled this requirement so that Jesus became an inheritor of the promises made to Abraham.
Abraham did become the father of several nations (see Gen. 25). In time, through a natural descendant of Abraham, the Lord Jesus, there came a Savior for all the peoples of the world. All nations, languages, and cultures may now choose to unite themselves to Christ, and through Him, to receive the blessing promised to Abraham. The Lord Jesus' circumcision permanently reminds us that God has fulfilled His promise to Abraham - all for our sake.
O Thou, Who art ever above the law, Thou hast submitted to it, granting us blessing from on high. Wherefore we extol Thee, praising Thy condescension of transcendent goodness!