Pope Shenouda III
The phrase “her firstborn Son”
(1) The phrase “her firstborn Son”
The Holy Bible clearly defines the meaning of the word firstborn. Prior to the establishment of Aaronic priesthood, the Divine Inspiration had said: “Sanctify to Me all the firstborn, whatever opens the womb among the children of Israel, both of man and of animal; it is Mine” (Ex.13: 2). Every firstborn was consecrated to God; dedicated to Him, whether or not a brother was born to him later. The parents did not wait until they begot him a brother, nor did the owner of the livestock wait until another offspring was born before offering and consecrating the firstborn to the Lord! But from his birth the firstborn was consecrated because he was the first offspring of the womb. Therefore there was a great possibility that any firstborn was an only son.
Thus the Lord Jesus Christ was the firstborn and the only Son. St. Jerome was right when he said: “Every only son is a firstborn but not every firstborn is an only son.” The expression ‘firstborn’ does not mean that another is born after him but it means that no sibling was born before him. That is why the firstborn of the unclean animals could be redeemed when they were one month old (Num. 18: 16,17), and the first offspring of the clean animals were to be offered as sacrifices to God without waiting until the birth of another offspring. He is the firstborn, whether or not one is born after him, because he is the first offspring of the womb.
In the same way, the Lord Jesus Christ is the firstborn of the Virgin. For when the Virgin and Joseph offered a sacrifice forty days after His birth, the Holy Bible tells us: “Now when the days of her purification according to the law of Moses were completed, they brought Him to Jerusalem to present Him to the Lord (as it is written in the law of the Lord, 'Every male who opens the womb shall be called holy to the Lord') and to offer a sacrifice according to what is said in the law of the Lord, ‘A pair of turtledoves or two young pigeons’ ” (Lk.2: 22-24).
It is clear that the law of the firstborn was applied to the Lord Jesus Christ forty days after His birth,
. Of course, there is no relation at all between the firstborn and the birth of siblings.
Here St. Jerome asks: “When God struck down the firstborn of the Egyptians, did He strike only those who had siblings or every male who opened the womb whether he had siblings or not?”