Parashat Shemini ends with the laws of permitted and forbidden animals, and how touching carcasses can cause impurity. Parashat Tazria starts with the laws of a new mother, and continues with the impurity associated with skin diseases (tzaraat). Why does the Torah place these regulations in this order?
Rashi on Vayikra 12:2 (following a midrash) gives the explanation that the Torah is following the order of Creation: first the animals were created, and then humans. So too, did the Torah give the laws of pure and impure animals in Parashat Shemini, and then follow them with the laws of pure and impure humans in Parashat Tazria.
However, as the Maharal points out in his Gur Aryeh commentary on Rashi, there are some difficulties with this answer. First of all, the fish and birds were created before the mammals, but Parashat Shemi lists unkosher mammals before the fish and birds (Vayikra 11:2-8 vs Vayikra 11:9-17). Secondly, Parashat Tazria begins with the laws of the impure woman (Vayikra 12) before the laws of the impure man (Vayikra 13), even though man was created before woman. So if the laws are intended to follow the story of Creation, it’s not a perfect fit.
Rabbi David Tzvi Hoffman offered a different answer. He said that the difference between Parashat Shemini and Parashat Tazria is as follows: In Parashat Shemini, the source of impurity is dead animals (either by eating or touching them), whereas in Parashat Tazria, live humans themselves lead to one becoming impure.
It may be understandable why dead animals can lead to impurity, but why should something as wonderful as childbirth do the same? One theory is that the process of childbirth, while providing life, contains elements of death – both in the blood lost, as well as an actual life leaving the mother’s body. Similarly, tzaraat is also considered like death, as Aharon said about Miriam when she was afflicted, “Let her not be as one dead” (Bamidbar 12:12).
All of this can help us answer a wider question. All of these laws are placed in the middle of a narrative – the death of Nadav and Avihu. What are they doing there? We’ll discuss that when we look at the transition to Parashat Acharei Mot.