While the goat designated by lot for Azazel shall be left standing alive before the LORD, to make expiation with it and to send it off to the wilderness for Azazel. (Lev 16:10 1985 JPS Tanakh)
To make expiation with it The idiom le-khapper ‘alav, translated “to make expiation with it,” is actually perplexing, as used in this verse. Almost without exception, kipper ‘al has to do with the use of sacrificial blood as a means of expiation, which is clearly not the case here. The scapegoat was not part of the expiation rites proper and was not slaughtered. It was merely stationed alongside the other goat and, like it, selected by lot.
Traditional commentaries express diverse views regarding this statement, which they recognize as representing exceptional usage. Targum Jonathan translates: “to atone for the sinfulness of the people, the House of Israel,” in which the preposition ‘alav, “upon it,” refers to the people, not the goat. Rashi notes that the verb kipper invokes confession, not only atonement, so that this verse could refer to the confession pronounced “over” the scapegoat, as prescribed in verse 21. Ibn Ezra emphasizes function: “That the goat takes on itself the expiation.” This is closer to what is being proposed here. The goat was an instrument of expiation—no rite of expiation involving blood was performed near it. (Baruch Levine, Leviticus [The JPS Torah Commentary; The Jewish Publication Society, 1989], 103)