The 71st prohibition is that a kohen who has a temporary blemish is forbidden from performing the Temple service as long as he still has it.
The source of this prohibition is G‑d's statement1 (exalted be He), "Anyone who has a blemish may not offer a sacrifice."
The Sifra says, "The phrase,2 'one who has a blemish may not approach,' only refers to one who has a permanent blemish. What is the source that one with a temporary blemish [may not perform the Temple service]? From the verse, 'Anyone who has a blemish may not offer a sacrifice.' " One who transgresses and performs the Temple service while he has a temporary blemish is also punished by lashes.
The regulations regarding temporary and permanent blemishes of a person are explained in the seventh chapter of tractate Bechoros.3
