Leviticus.
Chapter 12.
And the LORD spoke to Moses, saying, 
Speak to the children of Israel, saying, If a woman hath conceived seed, and borne a male-child; then she shall be unclean seven days; according to the days of the separation for her infirmity shall she be unclean. 
And in the eighth day the flesh of his foreskin shall be circumcised. 
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. 
But if she shall bear a female-child, then she shall be unclean two weeks, as in her separation: and she shall continue in the blood of her purifying sixty six days. 
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 turtle-dove, for a sin-offering, to the door of the tabernacle of the congregation, to the priest; 
Who shall offer it before the LORD, and make an atonement for her; and she shall be cleansed from the issue of her blood. This is the law for her that hath borne a male or a female. 
And if she shall not be 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. 
