When they enter the Tent of Meeting they shall wash with water, that they may not die … they shall wash their hands and feet, that they may not die. (E. 30:20)
Why is this a commandment? A death sentence for not washing hands and feet?
We might explain it by suggesting that a key role of the cohen, the priest, is to reconnect heaven and earth, specifically the “waters above and the waters below” that were separated during the Second Day of Creation.
The priest thus acts as a catalyst, a conduit, allowing for connection through their bodies and their service.
This might explain why the waters below must be contacted: by first “grounding” the exposed hands and feet before reaching upward, the priest can close the circuit with “the waters above” and fulfill their task.
If, on the other hand, they failed to first ground themselves in the waters below, then the proximity to raw divine energy would cause their souls to depart their bodies. Thus, the death sentence.