Leviticus is about the details of the Law. Way back in Exodus 20, the Law is introduced with the Ten Commandments; ten broad imperatives that govern both our relationship with God and with each other. When most people in church talk about “The Law,” they’re really talking about the Ten Commandments rather than the entire Law given at Mt. Sinai. In the New Testament, when Jesus (or anyone else for that matter) touches on the subject of “the Law”, most often they’re not talking about just the “big ten” from Exodus 20, but all 613 commands God gave Israel at Mt. Sinai. The Law moves from the broad general commands of Exodus 20 to an amazing degree of granularity and specificity in the very details of life. By the middle of Leviticus, we’re concerned about mold and fungus, skin rashes and hair loss.
As we read through Leviticus, we need to keep the words of 2 Peter 1:20-21 (ESV) in mind:
First of all you must understand this, that no prophecy of scripture is a matter of one’s own interpretation,
because no prophecy ever came by human will, but men and women moved by the Holy Spirit spoke from God.
2 Peter is talking specifically about the Old Testament prophecies that pointed to Jesus of Nazareth as God’s unique and chosen Son; such prophecies served to confirm what Peter (and the other Apostles) had witnessed. These prophecies didn’t come into being by the hand of any individual, but Peter says that the prophecies of the Old Testament were the intertwining of a person who spoke (or wrote) and God who gave a message.
From this, we understand that Scripture contains two things: a message from God and a very human context through and into which this message is given. With respect to Leviticus, we have both a message from God (broadly about what holiness looks like in all the different aspects of life) and a human speaker and context in which this message came. For example, from Leviticus 13:47-59 we know that mold growth in clothing was a problem. Imagine living in a world that has NONE of our modern tools (detergent, bleach, flowing water). Clothes could for a variety of reasons become contaminated with what they understood to be similar to leprosy. We know that mold is unrelated to skin disease, but God’s message (don’t ignore it, take care of it, respect the needs of the community for cleanliness and purity) is communicated through their worldview.
Mold must have been a major issue. Notice that it comes back up again in Leviticus 14:33 and following with respect to mold in a home (“a leprous disease in a house”). Again, we know that mold isn’t related to leprosy, but Leviticus was communicated through and to a community that had a pre-modern understanding of such things. From beginning to end, the Bible is God’s message communicated through human messengers and cultures. As you work your way through Leviticus, don’t miss watching for these two different “words” that come to us: what did this Late Bronze Age culture think about their world, and what did God say to them in that world.