Tumas mes differs from all other sources of defilement. For example, a kohen is not prohibited from touching a sheretz but is prohibited from touching a corpse. The purification process for one who touches a corpse is different. With other defilements, immersion in a mikvev removes the tumah. Tumas mes requires tevillah and sprinkling of mei chatos twice (days 3, 7) to permit entry to the Mikdash. Why did the Torah segregate tumas mes from all other forms of defilement in that immersion in a mikvev is insufficient to cleanse the individual? Why is the Torah so emphatic that we not take the sprinkling lightly and that we not equate tumas mes with other kinds of tumah? What special role does sprinkling play in attaining purity from defilement of a corpse?
To answer these questions we must ask why should man, the greatest of creatures, exist in distress and suffer a tragic existence? In the peculiar method of sprinkling, we find a hint as to the uniqueness of man as a great yet tragic figure. Besides the physical process differences between Immersion (tevillah) and sprinkling mei chatos (hazaya), there is a semantic difference. Tevillah and hazaya are distinct religious experiences.
For example, conversion requires tevillah, as does purification from contacting other major defining categories. The religious experience associated with tevillah is accomplished independently by the defiled individual acting as controlling object who enters the mikveh, while hazaya is performed by someone else and the defiled individual is the subject of that action. Tevillah requires that the tameh bow his head and knees and immerse himself. He emerges pure from the mikveh because of his own effort. If he refuses to immerse he can never attain purity.
Halachically, it is a reflexive act performed by the defiled individual; man defiles himself, man alone must clean himself. Engaging in tevillah demonstrates the human capability to change status and proactively self-elevate.
With regards to hazaya, the situation is reversed. The defiled can’t sprinkle chattos water on himself simply because he is defiled. Only someone else who is pure can sprinkle it on him. This is the antithesis of tevillah. In contra-distinction to other forms of impurity, the human who defiled himself by contacting a corpse is trapped in his defilement and can’t free himself. Without Parah Adumah and someone to assist him and sprinkle its ashes, man can’t escape the defilement of the corpse that holds him in its clutches.
Chazal equated defilement with sin and repentance; mikveh/tevillah, with teshuva. Ezekiel says that Hashem will sprinkle us with pure water and we shall be purified. Repentance from sin, like tumas mes, requires both immersion in a mikveh and sprinkling for complete repentance.
Man is both object, initiator, and subject, recipient. The sinner must take the initiative to repent, immerse in the mikveh; Hashem will complement his effort with forgiveness by sprinkling him with the ash water. If he is too vain to amend his ways and life style and take the first step of immersing himself in the mikveh as an independent object, Hashem will not help him.
The uniqueness of the experience confronting man who comes in contact with a corpse results in a defilement that is difficult to remove. Other defilements, e.g., sheretz and neveillah, typically precipitate a negative aesthetic experience. The experience is derived from the association of defilement with disease and decay of an organism in the process of decomposition and disintegration. A sheretz in this status is filth, squalor and causes unpleasant emotions to arise. All other defilements can be subsumed experientially under such unpleasantness (e.g., leprosy).
The experience associated with tumas mes extends beyond the abomination of the decomposing body. We experience something additional when we contact a dead human versus a dead animal. Man does not view death in the animal kingdom as a catastrophic loss. The termination of the specific organism has no impact as the continuity of the species. However, a human corpse indicates the end of a spiritual personality, no matter what he might have accomplished. A living person has an existential dimension that is self-aware and self-conscious, driven by vision and hope, a soul that grieves and despairs but lives in retrospection and anticipation; plans, builds and destroys worlds. Human death means destruction of a world. It is the most tragic human experience. Man who comes in contact with a human corpse becomes aware of his own finite existence. He knows that while he lives, he is committed to and has the opportunity to serve Hashem.