Though most of the Parsha speaks about the laws of the Metzora, one who becomes impure due a blemish on his body, it begins with a few lines about a woman becoming impure because of having a child, and the parsha is named for this small section.
The question is asked why we need the words, ki tazria – when she conceives. Let the Torah just say, “When a woman shall bear a son, she is impure for seven days, and on the eighth day he shall be circumcised.” One answer is, we learn that these laws don’t apply to a child born via Cesarean section. She will not become impure, and the child will not have a Bris on the eighth day if it falls on Shabbos.
However, we also learn, as R’ Shimon states, that the woman becomes impure even if she births something that is dissolved and resembles seed. Though no child was born, she will become impure anyway. Why is this so?
The commentaries give us some understanding of the impurity attached to menstruation. There was potential for new life and holiness, but when conception does not take place, and the eggs are released in blood, impurity takes the place of this potential greatness.
This message would apply to the woman who conceives but does not deliver a child as well. Though she was not a new mother, not having given birth to a son, she did have something with potential, and when that potential was lost, it leaves a vacuum of holiness which the impurity fills.
Perhaps this is why the portion of Tazria is placed at the beginning of the laws of Metzora. Tzaraas was caused by several different character flaws, such as arrogance, stinginess, and speaking ill of others. The common thread is not recognizing the greatness in others, and viewing them with a jaundiced or negative eye.
