When we speak about circumcision in Judaism, we almost always link it to Genesis 17, in which milah is a central feature of the covenant made between Abraham and God. The Hebrew word for covenant, brit, has become almost synonymous with this ritual act.
Finding the mitzvah of circumcision restated in Parashat Tazria complicates the picture. Here, milah is not presented as a distinctively special obligation, as the sign of the covenantal relationship between Israel and God, but as merely one mitzvah among a number of others. No explanation for it is given; if we look to the other laws in this section for enlightenment, we find details on ritual impurity, particularly around childbirth. This starkly different context lends itself to a completely different interpretation of circumcision: not covenantal act but purity act; not defining mark of Jewish identity but ancient blood ritual, somehow paralleling the rituals of menstrual purity.
But which is our circumcision – the circumcision of Genesis or that of Leviticus? The beauty of Judaism is that it can be both. Our traditions are able to bear multiple meanings and interpretations. The sages were comfortable with this. In midrashim they describe circumcision as being about covenant, fertility, purity, sacrifice, perfection, blood — all at the same time. And the medieval commentators added their own multiple explanations, as about health, hygiene, sex and so on.
Our practices do not need to mean the same thing to all of us at the same time. And like much that we do as Jews, circumcision too also has the potential for new and innovative understandings.