The "eighth day" with which SHEMINI opens was the first day of the month of Nissan, one year since they left Mitzraim. This was the day for the inauguration of the Bais Hamikdash following seven days of inaugaration of Aaron and his sons to become Kohanim. A fire consumes their Karbanos and the shechinah dwells in the Bais Hamikdash. Aaron’s two oldest sons, Nadav and Avihu, bring a Korban that Hashem told them not to and they die. Aaron is silent because of his tragedy. Hashem commands the kosher laws, identifying the animals permissible and forbidden for consumption. Land animals may be eaten only if they have split hooves and also chew their cud; fish must have fins and scales; a list of
non-kosher birds is given, and a list of kosher insects. Also in Shemini are some of the laws of the mikvah. Thus Bnei Yisrael are forced to differentiate between the impure and the pure.
Aaron and his surviving sons could not show mourning, because their job was to remain on a higher level in order to connect others to Hashem. But Bnai Yisrael had to mourn, because they are the ones who live in the world from which Nadav and Avihu had been torn. The sin of Nadav and Avihu is that they wanted to get rid of the separation between the G-dly world and the regular world and bring the entire world back into immediate unity with Hashem. They were drunk and did evil. Hashem does not want us to do evil, for He created it precisely so that we should reject it despite the temptations. Hashem created a separate world, a world with tempation as
a challenge for man, in which he must constantly be working on himself and his desire for materialism until he turns himself into a vessel fit to Hashem's liking. This cannot be done all at once: it must be done step by step, stage by stage.
The world consists of good and evil, pure and impure, holy and unholy. Our job is to find the pure and holy while rejecting the impure and unholy. We must be careful of the pig who displays its hoof as if to say, "I am pure". But the truth is that it's impure, for it does not chew its cud. We cannot allow ourselves to go by appearances in this world: we have to penetrate beneath the surface. The only means we have of doing so is with the Torah, which teaches the truth about good and evil in every area of life -- be it what we eat, how we do business, whom we marry and all other areas.
The biggest thing to have in mind is that Korban not only means sacrifice, it also means to bring closer. So when Bnei Yisrael brought a Korban, they were bringing themselves closer to Hashem. So every day, we must work on bringing ourselves closer to Hashem, step by step, stage by stage and do not let ourselves get tricked by the pig-by the material things that look like so much more fun than the ruchniustic things. Always have a goal in mind-becoming the best person you can be.
Have a lovely shabbas!!