The answer is: Upper lip

Lev 13:45 - Perhaps to cover mouth and prevent the spread of infection.

The practice of covering the upper lip when declaring “unclean, unclean” speaks volumes about communal responsibility in ancient Israel. This moment wasn’t just about a personal affliction; it served as a public health measure! The lepers had to announce their presence from a distance, highlighting society's efforts to mitigate the spread of contagious diseases, something that resonates clearly in today’s world.

In Leviticus 13:45, we find specific instructions regarding those who were deemed unclean, a term that Gnostics and early Christians might interpret in diverse spiritual ways about moral purity versus physical health. Yet, the call for community accountability is timeless. Here, we see a vivid image – the leper with their mouth covered likely symbolizing that while their diagnosis was out in the open, they wished to minimize the implications for others, reflecting profound empathy and care for the community at large.

Creating clean and safe spaces was vital; leprosy wasn’t merely about skin; it may have included other skin issues like psoriasis. Such laws were part of a larger system of care—teaching compassion in handling exclusion. Echoes of this theme call to mind the way we treat others who are marginalized today. To this day, "lepers" exist in the forms of stigma, representing those on the outskirts of society. Addressing human ailments, both visible and hidden, is at the core of our collective humanity!