265. The Waiting Game: The prohibition against a purified kohein serving before sunset

In verses 21:5-6, we have a list of several things the kohanim are not to do (not tear out hair or cut their flesh, for example), followed by a statement that they are not to desecrate God’s Name because they perform the Temple service. What exactly entails desecrating God’s Name is not obvious from the verse itself but the Oral Law tells us that it means that a kohein who has been purified from a form of ritual uncleanliness may not serve until after the sun goes down. (See Talmud Sanhedrin 83b.)

When a person became ritually impure, he would ultimately purify himself through immersion in a mikvah. This was done by day and it lessened the degree of ritual impurity on the person but the impurity did not completely depart until nightfall. A person who has gone to the mikvah but who has not yet been purified by nightfall is called a tevul yom. A kohein may not serve as a tevul yom.

The reason for this mitzvah is that the kohein acts as the agent of the people when it comes to the Temple service. He must be at peak spiritual capacity to serve and a tevul yom, while almost there, isn’t quite there yet. For him to serve even in a partial state of impurity is a disservice to those he is meant to represent.

If utensils used in the Temple service became ritually impure and were immersed, they must likewise wait until nightfall before being used.

This mitzvah only applies to kohanim in Temple times. It is discussed in the Talmud in tractate Sanhedrin (83b). It is codified in the the Mishneh Torah in the fourth chapter of Hilchos Biyas HaMikdash and is #76 of the 365 negative mitzvos in the Rambam’s Sefer HaMitzvos.