Dora Bas Rivka Silver O'H
Thanks a Lot!
One type of peace offering was the korban todah, a sacrifice to give thanks. Such an offering must include various types of loaves and matzos mixed with oil (40 in all). A portion of these would go to the kohein who offers the sacrifice. The korban todah had to be eaten on the day it was offered; it was not permitted to be left overnight.
If the peace offering was merely brought to fulfill a vow, it could be eaten on the day it was offered and on the next. Whatever remained on the third day had to be burned. If the person who brought the offering so much as intended to eat it after the prescribed time, the sacrifice was unacceptable to G-d. It is "piggul" - detestable - and the person bears responsibility for his actions.
If the meat of a sacrifice touches something ritually impure, it must be burned. If a person ate flesh from a peace offering while in a state of ritual impurity, he would be subject to the penalty of kareis.
After relating all these laws pertaining to sacrifices, G-d gave Moshe instructions for the Jews not to eat certain fats called cheilev (see also 3:17). They're allowed to use these fats, just not to eat them. Furthermore, Jews may not eat blood, whether from animals or birds.
Returning to peace offerings, G-d said that the person who brings such an offering must personally wave certain parts to be burned on the animal's chest. After burning those parts, the chest of the sacrifice would belong to the kohein, as would the right leg.
G-d communicated all these laws, about the various sacrifices, to Moshe on Mt. Sinai when He first commanded that Israel was to offer sacrifices; they were merely reviewed at this time.