The Perasha begins with a description of the service of the Kohanim on the eight day of the inauguration of the Mishkan, hence the name of the perasha – Shemini.
Immediately after, we are told that Aharon’s sons, Nadab and Abihu die because they “brought a foreign fire” to the Tabernacle in their hurry to participate in the festivities of the inauguration. Hashem commands Aharon on the prohibition of drinking alcohol while performing the services in the Mishkan so that they will never be confused in their tasks.
Subsequently, the Torah describes in depth the laws of Kashrut. The two characteristics that have to be present for an animal to be considered Kasher are, split hooves, and chewing its cud. The Torah prohibits the eating of an animal which contain only one of those characteristics. There are only 4 animals that have only one of those characteristics; namely the rabbit, the hyrax and the camel, only chew their cud and the pig only has split hooves. In thousands of years there has not been any other species discovered that have only one of those characteristics.
For the fish in the sea, only fish with scales and fins are considered acceptable to eat; all other fish and seafood are forbidden. The Torah lists all birds which are forbidden, as well as a list of permissible insects. The laws of טומאה – impurity or contamination, and טהרה – purity or sterility, are described. Utensils and items which can become contaminated/impure are listed. The prohibition of eating creeping creatures is emphasized. Hashem reminds Bene Yisrael that He is Holy, and therefore they too must be holy, and free of contaminants/impurities.