And the LORD spake unto Moses, saying,
From uncleanness contracted by the touching or eating of external things, he now comes to that uncleanness which ariseth from ourselves.
 Speak unto the children of Israel, saying, If a woman have conceived seed, and born a man child: then she shall be unclean seven days; according to the days of the separation for her infirmity shall she be unclean.
Seven days — Not for any filthiness which was either in the conception, or in bringing forth, but to signify the universal and deep pollution of man's nature, even from the birth, and from the conception. Seven days or thereabouts, nature is employed in the purgation of most women.
Her infirmity — Her monthly infirmity. And it may note an agreement therewith not only in the time, Leviticus 15:19, but in the degree of uncleanness.
 And she shall then continue in the blood of her purifying three and thirty days; she shall touch no hallowed thing, nor come into the sanctuary, until the days of her purifying be fulfilled.
In the blood of her purifying — In her polluted and separated estate; for the word blood or bloods signifies both guilt, and uncleanness, as here and elsewhere. And it is called the blood of her purifying, because by the expulsion or purgation of that blood, which is done by degrees, she is purified.
No hallowed thing — She shall not eat any part of the peace-offerings which she or her husband offered, which otherwise she might have done; and, if she be a priest's wife, she shall not eat any of the tythes or first fruits, or part of the hallowed meats, which at other times she together with her husband might eat.
 But if she bear a maid child, then she shall be unclean two weeks, as in her separation: and she shall continue in the blood of her purifying threescore and six days.
Threescore and six days — The time in both particulars is double to the former, not so much from natural causes, as to put an honour upon the sacrament of circumcision, which being administered to the males, did put an end to that pollution sooner than otherwise had been.
 And when the days of her purifying are fulfilled, for a son, or for a daughter, she shall bring a lamb of the first year for a burnt offering, and a young pigeon, or a turtledove, for a sin offering, unto the door of the tabernacle of the congregation, unto the priest:
For a son or a daughter — For the birth of a son, or of a daughter: but the purification was for herself, as appears from the following verses.
A sin-offering — Because of her ceremonial uncleanness, which required a ceremonial expiation.
 And if she be not able to bring a lamb, then she shall bring two turtles, or two young pigeons; the one for the burnt offering, and the other for a sin offering: and the priest shall make an atonement for her, and she shall be clean.
The morality of this law obliges women who have received mercies from God in child-bearing, with all thankfulness to acknowledge his goodness to them, owning themselves unworthy of it, and (which is the best purification) to continue in faith, and love, and holiness, with sobriety.