"They shall separate themselves from the things which the children of Israel make holy, and they shall not profane My holy name"—Leviticus 22:2.
A ritually impure priest is forbidden from performing any service in the Holy Temple.
"They shall not profane the name of their G‑d"—Leviticus 21:6.
[A tevul yom is an individual who was impure and immersed himself in a mikvah (ritual pool). Though he is now pure, there are still certain restrictions upon him until the sun sets that day.]
A priest who is a tevul yom, though pure, is forbidden from doing any service in the Holy Temple until the sun sets.
"And Aaron and his sons will use it to wash their hands and feet when they enter the Tent of the Assembly"—Exodus 30:19.
The kohanim (priests) are commanded to wash their hands and feet before entering the Holy Temple's sanctuary and before commencing any of their Temple duties.
"He shall not approach the curtain, nor come near to the altar..."—Leviticus 21:23.
A priest who possesses a physical blemish is forbidden from entering the Holy Temple's sanctuary or the area between the Outer Altar (including the altar) and the Sanctuary.
"...who has any blemish shall not approach"—Leviticus 21:17.
A priest who possesses a physical blemish is forbidden from serving in the Holy Temple.
"Any man that has a blemish, shall not approach"—Leviticus 21:18.
A priest who possesses a temporary physical blemish is forbidden from serving in the Holy Temple—so long as the blemish exists.
