“And he shall slaughter it before him (Numbers 19:3).” Rashi explains that a Zar, or non-cohen, slaughters the Red Heifer while Elazar, the son of Aaron, the Kohen Gadol, looks on.
This passage can be interpreted by reference to the view that when the soul leaves the body, a man beholds the Divine Presence. But only if he has lived righteously; then he is worthy to behold the countenance of the Divine Presence at the time of his death, and his soul cleaves to it. Thus, the Torah instructs, “And he shall slay it before him,” that the stranger slays; the stranger is the Angel of Death. But, “Elazar looks on,” meaning, the dying person looks on the Divine Presence, symbolized by the name El-azar – God Who Helps. (Avodat Yisrael, Parshat Parah)