The law of the red heifer is the most mysterious law of the Torah. Somehow, the red heifer would purify one who contracted the most severe form of ritual impurity, that of coming in contact with a human corpse.
Life is synonymous with holiness, for G‑d is the source of life. The red heifer represents the power to purify even the most severe form of ritual impurity, represented by death, the antithesis of holiness and life.
Indeed, Chassidic philosophy explains that the red heifer captures the secret of the uniquely Jewish approach to purifying the negativity within each of us. It is the key to dealing with our inner passions, which overwhelm us with the force of their energy.
What were the requirements for the red heifer? The Torah tells us:
The L‑rd spoke to Moses and Aaron, saying: This is the statute of the Torah that the L‑rd commanded, saying, “Speak to the children of Israel and have them take for you a perfectly red, unblemished cow, upon which no yoke was laid.”
The heifer must be red, it must be unblemished, and it must never have been burdened by a yoke. Red is the color of passion. The heifer represents the animalistic emotions within the human heart. A yoke represents the taming of the animal.
At times we look inside ourselves, and we experience the emotional intensity of our animalistic urges and cravings. We look at our inner red heifer and we fear that its raw, animalistic energy is too powerful for us to control; we see nothing but impurity.
The Torah’s insight into the red heifer is as profound as it is revolutionary:
The cow shall then be burned in his presence; its hide, its flesh, its blood, with its dung he shall burn it . . . They shall take for that unclean person from the ashes of the burnt purification offering, and it shall be placed in a vessel [filled] with spring water . . . A ritually clean person shall take the hyssop and dip it into the water and sprinkle it on the tent, on all the vessels, and on the people who were in it, and on anyone who touched the bone, the slain person, the corpse, or the grave.
Purity is not achieved by suppressing or waging war against desire. The Torah teaches us to look right at the passionate, forceful red heifer. Look at its core and understand that the red heifer is not negative, nor is it spiritually neutral. The Torah wants us to understand that the heifer can be the most powerful agent of purity in our life. The power of desire, its incredible force and energy, is not evil. For while the external expression of the desire may be negative and must be burned, the ashes of the heifer, its inner essence, is the source of purity. When the ashes are mixed into the “living waters,” when the power of desire is directed toward a positive goal, the heifer itself will be an unbridled force that will provide spiritual and emotional purity.
-adapted from www.chabad.org