Vayikra - R'vi'i
Peace, Baby!
A korban shlamim ("peace offering") could be brought from either male or female cattle, so long as they were free of imperfections. The owner would place his hands on the animal's head before giving it over to the kohanim for sacrificing. The parts burned included the stomach fat and other intestinal fats, the kidneys and the lobe of the liver. A person could also bring a male or female sheep as a korban shlamim. If he brought a sheep, he would also have to include the fat tail among the parts to be burned.
The internal fats that were burned as part of the korban shlamim are perpetually forbidden to be eaten, in all times and contexts, just like blood. (The forbidden fats are called cheilev in Hebrew; fats that may be eaten are called shuman. See also 7:22.)