Deuteronomy 12:17 "You may not eat within your gates...the first-born of your herds or flocks"

Sometimes, portions of the sacrifices are eaten by the priests and others, by the person who brings them.

The sin-offerings and guilt-offerings must be eaten in the specific area of the Beit HaMikdash called the "Azarah," the Temple courtyard.

We are cautioned not to eat this sacrificial meat anywhere outside this area. (This Negative Mitzvah applies to priests as well.)