Rabbi Assi advanced a surprising claim: the slaughtering of sacrificial animals also took place on top of the altar, not merely beside it. This contradicted the common understanding that slaughter happened at ground level before the animal was placed on the altar for burning.
Rabbi Assi found support in the Torah's own language. (Exodus 20:21) says: "An altar of earth shall you make for Me, and you shall slaughter therein your burnt-offerings and your peace-offerings." The word "therein" — on or within the altar itself — implies that the act of slaughter occurred on the altar, not merely near it.
But this creates a tension between two verses. One verse mentions "your burnt-offerings and your peace-offerings" in connection with the altar. Another states "And you shall offer your burnt-offerings — the flesh and the blood." How are these two to be reconciled? The Mekhilta leaves the question open, presenting it as an unresolved challenge within the legal tradition.
Rabbi Assi's opinion was not universally accepted, but its inclusion in the Mekhilta demonstrates the text's commitment to preserving minority views. Even positions that most authorities rejected were recorded and transmitted. The altar was not just a place of fire and smoke — it was a locus of intense legal debate, where the precise choreography of sacred service was argued over with the same rigor that later generations would bring to every detail of Jewish law.