Some people think that if they were truly spiritual, they would never eat.
In truth, few acts are as divine as eating food.
Eating is similar to sifting gold. You grasp the divine spark within a food and reject the dross. And then, in the mitzvahs energized by that food, you carry that divine spark back to its origin within the oneness of its Creator.
That is why there are foods that are forbidden and foods that are permissible. The Hebrew word for “forbidden” is assur—meaning tied down. “Permissible” is mutar—untied.
Kosher means “fit.” Foods that are assur are not fit for the divine act of eating because the divine spark within them is tied down and cannot be released. If we would eat them, rather than carrying that spark upward, we would be pulled down with it.
But foods that are mutar are fit and ready to release powerful divine energy into all the mitzvahs we do.
Why is the spark tied down in a non kosher foods?
That is what makes them non-kosher.
Everything must have a divine spark—because everything receives its existence from G‑d. But in some things, that spark is very hidden and inaccessible. So they appear to be evil.
Eventually, those sparks, as well, will be rescued. At that time, all evil will vanish as though it never was.
Rabbi, Is there a source that anything other than the pig will become tahor and permissible to eat?
The Rebbe (Igros Kodesh Volume 3 Letter 507) writes that since the verse states: "I will remove the spirit of impurity from the land" (Zechariah 13:2), in the second era of Moshiach, after the resurrection, there will be no more impure animals and all animals will become kosher. In the first era of Moshiach, on the other hand, only the pig will become kosher.
Thank you.