And the 128th prohibition is that we are forbidden from feeding meat from the Pesach offering to a Jew who has converted [to another religion].
The source of this commandment is G‑d's statement1 (exalted be He), "Any ben neichar ("Foreigner") may not eat it." The one who explains the Oral Tradition [i.e. Onkelos] says [the phrase, "Any ben neichar means], "any Jew who has converted."3 In the words of the Mechilta,4 "The phrase, 'Any ben neichar,' refers to a Jew who has converted and worshiped idolatry."5