Parshas Shemini juxtaposes the story of the deaths of Nadav and Avihu with the laws of kashrus. Nadav and Avihu were consumed by divine fire for offering “aish zarah”, strange fire, to Hashem. The nature of the aish zarah is not specified in the verse and is the subject of much midrash. What is clear is that Hashem specified that which was acceptable to offer to him and this offering was not included in that list. It is a hoq—a law of Hashem with no clear explanation for its origin.
We are soon presented with another list, this of creatures we are permitted to eat and others which we are not. Again, there is much midrash as to why a cow might be permitted and a pig not or why a locust might be permitted but a lobster not. In the end, though, we can only say that the list is a hoq—a law of Hashem with no clear explanation for its origin.