For it is the life of all flesh; the blood of it is for the life thereof: therefore I said unto the children of Israel, Ye shall eat the blood of no manner of flesh: for the life of all flesh is the blood thereof: whosoever eateth it shall be cut off.
Because blood is what keeps animals alive, I told the people of Israel not to eat any blood from any kind of animal. Doing so would mean cutting them off from their community.