When the days of her purification ... — The primary idea of the law of Leviticus 12:1-6, would seem to have been that of witnessing to the taint of imperfection and sin attaching to every child of man, just as that of circumcision (its merely physical aspects being put aside) was that of the repression or control of one chief element of that sinfulness. Here neither was necessary; but the whole mystery of the birth was not as yet revealed to Mary, and therefore her act was simply one of devout obedience to the law under which she lived. The period of purification lasted for forty days from the birth, bringing the Feast of the Purification in our Church Calendar to February 2nd.
To present him to the Lord. — This, as the next verse shows, was only done according to the law of Exodus 13:2, when the firstborn child was a son. It was obviously a witness of the idea of the priesthood of the firstborn — a survival of the idea in practice, even after the functions of that priesthood had been superseded by the priesthood of the sons of Aaron. The firstborn of every house had still a dedicated life, and was to think of himself as consecrated to special duties. Comp. Hebrews 12:23 as giving the expansion of the thought to the whole company of those who are the “firstborn,” as they are also the “firstfruits” of humanity (James 1:18). As a formal expression of the obligation thus devolving on them, they had to be redeemed by the payment of five shekels to the actual Aaronic priesthood (Numbers 18:15).