Rambam - Sefer HaMitzvos: Negative Mitzvot 181, 182, 184, 185, 183: Negative Mitzvot 181, 182, 184, 185, 183

Negative Mitzvah 181: It is forbidden to eat "Terefah"
Exodus 22:30 "Neither shall you eat any meat that is torn in the field"

An animal that is attacked and killed by another animal is called a "terefah".

If it suffered a serious wound, we are forbidden to eat from its meat, even though it continues to live and is then slaughtered properly.

The same idea applies to an animal which suffers other serious wounds. If they are likely to cause the animal's death, it is considered terefah and may not be eaten, even if it is slaughtered properly.

There are other instances where an animal may be considered terefah and this Negative Mitzvah also forbids eating from them.

Negative Mitzvah 182: It is forbidden to eat meat that has been cut from a living animal
Deuteronomy 12:23 "And you may not eat the life with the meat"

We are forbidden to cut a limb or flesh off of a living animal and then eat it.

Negative Mitzvah 184: It is forbidden to eat blood
Leviticus 7:26 "You shall not eat any blood"

We are forbidden to eat any blood.

When an animal is slaughtered, its blood is poured away.

Afterwards, we must soak and salt the meat. This process drains the blood which is in the meat. After the meat is soaked and salted it is considered properly "koshered" and fit to eat.

Do you know that even eggs may have blood stains?

It is necessary to check eggs before eating or cooking them.

If blood spots are found, and cannot be removed, we should throw out the egg.

Negative Mitzvah 185: It is forbidden to eat "Chelev"
Leviticus 7:23 "You shall eat no fat of an ox, or sheep, or goat"

There are certain parts of a kosher animal which we are not allowed to eat.

This Negative Mitzvah concerns the "chelev" or "hard fat" of the animal.

We are forbidden to eat the chelev. The chelev was part of the sacrifices that were offered in the Beit HaMikdash.

Negative Mitzvah 183: It is forbidden to eat the "Gid-HaNasheh"
Genesis 32:33 "Therefore the children of Israel shall not eat the sinew of the thigh-vein"

When Jacob fought with the angel, (see Genesis 32), the angel pushed his hip out of place.

Despite this wound, Jacob continued his battle with the angel and forced the angel to admit defeat.

This Negative Mitzvah commemorates that victory.

On the hind part of an animal, there is a large main nerve running down the back of its leg. This is called the Gid-HaNasheh.

Before we eat meat from this part of the animal, we must remove that nerve. Since it is difficult to do this, many Jews avoid eating the meat that comes from that area.

There are times when the most destructive impulses within us come dressed in a prayer shawl.
When it is time to rejoice, and a voice tells you to feel remorse over your sins. When it is time for remorse, and it tells you, "Who do you think you are, that you should feel remorse?" When there is someone who desperately needs your help and you decide it is time to meditate. When it is time to meditate, and you decide you must go out to save the world. When you have attained a grasp of a deep concept, or prayed to G-d with great fervor, or secretly performed a beautiful deed -- and a voice inside says, "Boy, are you good!"
There is only one thing that voice inside will never tell you to do and will only do everything it can to obstruct. It will never say to break the chains with which it has bound you and change yourself.

From: Bringing Heaven Down to Earth by Tzvi Freeman - tzvif@aol.com