The Parah Adumah or Red Heifer is the classic example of a Mitzvah which is beyond our comprehension.
As described in the Bamidbar (19:1-22), the cow had to be slaughtered outside the camp and its blood sprinkled in the direction of the holy of holies in the Tabernacle. In Temple times, the holy of holies in the Temple.
The cow was then burned whole together with cedar wood, a crimson thread, and hyssop. The ashes were mixed in a vessel containing spring water.
The great paradox of the whole rite is that the Kohanim who performed the purification became themselves defiled. This mystery, that the parah adumah purified the defiled and yet defiled the pure was, for the Rabbis, the supreme example of the unfathomable in connection with some of the divine commands.
Even the wise King Solomon, say the Rabbis, was unable to explain the rite. (Yoma 14A)
‘It is a decree of the Holy One, blessed be He, who declared: I have set it down as a statute, I have issued it as a decree which you are not to question.’
As humans we were created as finite beings. We can only see so far, run so fast or think so deeply. In a finite world there is black and white; good and bad; light and dark; pure and impure. Distinctions and un-blurred edges are the natural result of our finiteness.
G-d is infinite. In His world everything is one. By G-d there is no good and evil and no pure and impure. For limited humans infinity is too much. Even the wisdom of Solomon is finite and can not comprehend the infinite.
The masters of Kabbalah explain that although we cannot comprehend the infinite we can still touch it and make it part of our lives. Indeed, our Neshamos are connected to the Infinite one.
Imagine a toddler holding the hand of his grown father. He can not necessarily articulate or comprehend the love, the dedication or the wisdom of his father; yet by holding his hand he can still feel attached, secure and comforted by his touch.
Through the Mitzvot of the Torah we can touch infinity, create eternity and hold hands with the Infinite One.
Infinity and eternity are two ends of the same rope.
Shlomo Hamelech was the master of wisdom in this world. He built the Beis HaMikdash so that Heaven can touch Earth. Through the Mitzvot of the Beis Hamikdash, we on Earth can touch Heaven.
The Red Heifer represented the infinity that we can touch. Pure became impure and impure became pure because in G-d’s world everything is One.