What, then, is the reason for the Aramaic of the ha laḥma anya? The only one given by Jewish tradition that I know of first appears in the 13th-century Maḥzor Vitry, an all-year-’round prayer book with extensive commentary attributed to the French rabbi Simḥah ben Shmuel of Vitry, a student of Rashi. Writing about the Haggadah’s opening lines, he says:It seems to be an inference based on the Talmud's statement that angels don't know Aramaic. Cross-file under Passover.Aramaic was ordained because were one to say in Hebrew “Let whoever is hungry come and eat,” it would be as though also inviting the evil spirits. . . . But the evil spirits do not know Aramaic.We do not welcome strangers to our seder in Hebrew, in other words, because the world’s demonic legions, who understand Hebrew and Hebrew alone, might then decide to crash the party. What a charming but strange notion! Where does it come from?
By the way, it is good to see Philologos active again. He was last noted by PaleoJudaica back in 2014. It seems he has moved from The Forward to Mosaic Magazine, which is news to me.