Life starts with contamination. It starts out dirty. Childbirth is messy. It’s not sinful; it’s just a fact of life.
The general Bible term for infections of skin and surfaces is “leprosy,” but it covers a host of conditions. It’s also a good parable for “rot” in our character — if the lesson isn’t taken too far.
The Torah reading תזריע Tazria (“she will conceive,” Leviticus 12–13) is concerned about what is physically dirty vs. clean, but the LORD’s lesson for us is more than skin-deep.
In Leviticus 10, Aharon (Aaron) and his sons were ordained as priests. In Leviticus 11-12, they are charged with teaching the people of God to distinguish holy from unholy, “clean” from “unclean.” Once we have been taught by our High Priest, Yeshua the Mashiakh (Jesus the Christ), about what is holy and clean, we need to live in that truth. From this we learn how holiness can be just skin-deep if the heart doesn’t change.
This text could be called the “leprosy” text, except that it’s about more than examining one’s skin. There are spiritual applications, too. An example is the need to examine our hearts to see if we have surface sin or deep ingrained sin that we need our High Priest Yeshua to diagnose and atone. Sometimes we need to isolate ourselves and contemplate the issue deeply for seven to 14 days to wrestle with the issue.
God calls us “priests and kings.” But there is only one true High Priest, Yeshua, and He is the one who declares us “clean” or “unclean.”