Comentario sobre Levítico 19:33

לא תונו [AND IF A STRANGER SOJOURN WITH THEE IN THY LAND], YE SHALL NOT VEX HIM — This implies vexing him with words (cf. Rashi on Exodus 22:20) — do not say to him, “Yesterday you were an idolator and now you come to study the Torah which was given from the mouth of the Almighty!” (Sifra, Kedoshim, Chapter 8 2; Bava Metzia 58b, 59b.)

After the Torah warned that the Torah scholars, etc., must be shown due respect, it also warns us not to treat with disdain people who are on the lower rung of the economic ladder. וכי יגור אתך גר לא תונו אותו, even if this unfair treatment consists only of words, not deeds. The Torah continues,

וכי יגור אתך גר, "And if a proselyte sojourn with you in your land, etc." The Torah commences with the singular, i.e. אתך, amongst you (sing), while switching to plural, i.e. ארצכם, "your country" (pl); the reason is that proselytes have been attracted to Judaism through the original proselyte, the first Jew, Abraham, the "spiritual father" of all proselytes. Another factor in attracting pagans to convert to Judaism is the Holy Land itself. We perceive all the souls of the converts as having been "captured" souls which had been ensnared by Satan either in bulk as a result of Adam's sin or individually on subsequent occasions. The word אתך alludes to Abraham's ability to attract converts, the word ארצכם to the ability of the land of Israel itself to exert such an influence.