3,999. Serving in Unknown Impurity

Hilchos Bias HaMikdash 4:5

We infer that the service of one who needs to bring an offering to complete his purification is disqualified from Leviticus 12:8: “The kohein shall atone for her and she will be pure.” Before the sacrifice, she wasn’t pure. The same is true of all who still need to bring their offerings.

Hilchos Bias HaMikdash 4:6

Let’s say that a kohein performed the service and it was subsequently discovered that he was ritually unclean. If the cause of the impurity is known, all the sacrifices he offered are disqualified because he profaned the service. However, if he was rendered unclean from a source of impurity that no one knows about, the tzitz (the plate worn on the Kohein Gadol’s forehead) atones for it and the sacrifices that he offered are accepted. This is the case even if he became aware of his impurity before sprinkling the blood on the altar and then he sprinkled it. This is because the tzitz atones for unknown impurity even if one acts intentionally. The definition of unknown impurity was already discussed in Hilchos Nezirus.