A sign on a door tells us what's inside. A storefront with the word SHOES on its entrance explains what we can expect to find in this store. Of course, it’s not the signs that make things into what they are. The signs simply describe what is already there.
Parshat Shemini, this week's Torah portion, tells us about the signs of kosher animals. Kosher animals have two signs: they have split hooves and they chew their cud. The signs that tell us if a fish is kosher, are fins and scales.
However, it is not the signs that make the animal kosher. G-d created these animals with a kosher nature. The signs merely tell us that they are kosher.
When we eat the meat of any animal, its nature becomes part of us, and it affects the way we think. We are what we eat. The meat of kosher animals is fit for a Jew to eat, because of its kosher nature. When we eat this food, it affects us in the proper way. So, G-d gave those animals signs to inform us that they are kosher.
Other animals were created with non-kosher natures. This means that their meat will not affect us in a good way.
Kosher animals have split hooves, which means that their feet are divided. We can divide our activities throughout the day into two categories. One category includes praying, studying Torah, giving charity and helping others. The other category includes mundane activities such as eating, playing, reading, and doing business etc.
Though they are different types of activities, they should be like two parts of a one single hoof. Meaning, that just as we pray, study and do holy activities we must also do the mundane activities in a holy way, like a Jew. The foods we eat, the words we use, the places we go and the way we conduct our business should all belong to one kosher, holy, lifestyle.
The second kosher sign, chewing the cud, teaches us that just as animals take time to chew their cud, bringing up their food over and over again, we too must take the time, to think things over and plan to do things in a way which is kosher fit for a Jew.
Thus, through having split hooves and chewing the cud, internally, we come to keep kosher not just in our kitchen but in our whole life.