וְכִֽי־יָג֧וּר אִתְּךָ֛ גֵּ֖ר בְּאַרְצְכֶ֑ם לֹ֥א תוֹנ֖וּ אֹתֽוֹ׃
At kapag ang isang dayuhan ay nanirahan kasama mo sa inyong lupain, huwag ninyo siyang aapihin.
Rashi
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.)
Alshekh
If a proselyte comes to live. You might raise the question: Since idolatry is so reprehensible it should cause the proselyte to be culpable as well! But [the answer is that] when the proselyte converts he becomes like a new-born child, for he is given a new soul from below the wings of the Divine Presence. The impure soul is taken away from him. Therefore, he has a portion like you in your Land of Truth.
Sforno
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,