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.
Related Commentaries of Leviticus 12:2
Leviticus 12:2
2 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.