And you shall give it to Elazar the Kohen, and he shall take it outside the camp and slaughter it before him.
Torah Temimah: Zevachim 113a — If one slaughtered the para not opposite the entrance of the Heichal it is invalid, as it says “and he shall slaughter… and he shall sprinkle,” equating its slaughter to its sprinkling: just as its sprinkling is opposite the entrance, so its slaughter is opposite the entrance.
English: If one slaughtered the para not opposite the entrance of the Heichal it is invalid, as it is said “and he shall slaughter… and he shall sprinkle,” equating its slaughter to its sprinkling: just as its sprinkling is opposite the entrance, so its slaughter is opposite the entrance.
Hekesh between slaughter and sprinkling.
The shechitah of the para aduma must be performed facing the entrance of the Heichal, parallel to the requirement for the blood sprinkling.