משנה אויף במדבר 18:7

If one steals the sacred vessel called a “kasvah” (Numbers 4:7), or cursed by the name of an idol, or has sexual relations with an Aramean (non-Jewish) woman, he is punished by zealots. If a priest performed the temple service while impure, his fellow priests do not bring him to the court, but rather the young priests take him out into the courtyard and split his skull with clubs. A layman who performed the service in the Temple: Rabbi Akiva says: “He is strangled.” But the Sages say: “[His death is] at the hands of heaven.”

“Before time” applies both to [the animal] itself and to its owner. What is “before time” as applied to its owner? If a zav or a zavah, a woman after childbirth, or a metzora, offered their hatat or their asham outside [before the time in which they were obligated], they are exempt; [If they offered] their olah or their shelamims outside [before their time], they are liable. One who offers up flesh of a hatat, or flesh of an asham, or flesh of most holy sacrifices, or flesh of less holy sacrifices; or the remainder of the omer, or the two loaves, or the showbread, or the remainder of meal-offerings; Or if he pours [the oil on to the meal-offering], or mingles [it with flour], or breaks up [the meal-offering cakes], or salts [the meal-offering], or waves it, or presents it; or sets the table [with the showbread], or trims the lamps, or takes out the fistful, or receives the blood; [If he does any of these] outside, he is exempt. One is also not liable for any of these acts on account of not being a priest, or uncleanness, or lack of [priestly] vestments, or the non-washing of hands and feet.