A Non-Priest Serving in the Holy Temple
"And a stranger shall not come near to you"—Numbers 18:4.
It is forbidden for anyone not of the seed of Aaron [i.e., a non-priest] to serve in the Holy Temple in the capacity of a priest.
Unblemished Sacrifices
"It shall be perfect to be accepted"—Leviticus 22:21.
When offering a sacrifice, we are required to ensure that it is "complete"—devoid of any of the blemishes enumerated in the Torah (as well as those blemishes not written explicitly in the Torah, but included by Mosaic tradition).
The same is true regarding the wine libations and the oil and flour used in the meal offerings—they are to be of premium quality and free of any defect.
Designating a Blemished Animal for a Sacrifice
"Whatever has a blemish you shall not offer"—Leviticus 22:20.
It is forbidden to designate (i.e., sanctify) an animal with a permanent blemish for a sacrifice.
Slaughtering a Blemished Animal for a Sacrifice
"You shall not offer these to G‑d"—Leviticus 22:22.
It is forbidden to slaughter an animal with a permanent blemish for a sacrifice.
Sprinkling the Blood of a Blemished Animal on the Altar
"You shall not offer to G‑d"—Leviticus 22:24.
It is forbidden to sprinkle the blood of an animal with a permanent blemish on the altar.