But if she bears a female child, then she shall be unclean two weeks, as in her menstruation. And she shall continue in the blood of her purifying for sixty-six days.
The law here pronounces women lying-in ceremonially unclean. The Jews say, "The law extended even to an abortion, if the child was so formed as that the sex was distinguishable." 1. There was some time of strict separation immediately after the birth, which continued seven days for a son and fourteen for a daughter, Lev 12:2, Lev 12:5.
Commenting on Leviticus 12:1-5
And when the days of her purifying are fulfilled, for a son, or for a daughter,.... For a son forty days, and for a daughter eighty; but the ancient Jews formerly, that they might not break it, ordered, that the offering enjoined as follows should not be brought until the next day after the time was up: their canon runs thus (t),"a new mother does...
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. (e) Twice as long as if she gave birth to a boy.