The Talmud teaches that the Torah warns against oppressing the ger (stranger/non-Jew dwelling among Israel) in thirty-six — or forty-six — places, underscoring the severity of this prohibition.
תָּנוּ רַבָּנַן: הַמְאַנֶּה אֶת הַגֵּר, עוֹבֵר בִּשְׁלֹשָׁה לָאוִין. וְהַלּוֹחֲצוֹ, עוֹבֵר בִּשְׁנַיִם. מַאי שְׁנָא מְאַנֶּה, דִּכְתִיבִי שְׁלֹשָׁה לָאוִין: ״וְגֵר לֹא תוֹנֶה״, ״וְכִי יָגוּר אִתְּךָ גֵּר בְּאַרְצְכֶם לֹא תוֹנוּ אֹתוֹ״, ״וְלֹא תוֹנוּ אִישׁ אֶת עֲמִיתוֹ״, וְגֵר בִּכְלַל עֲמִיתוֹ הוּא. לוֹחֲצוֹ נָמֵי שְׁלֹשָׁה כְּתִיבִי: ״וְלֹא תִלְחָצֶנּוּ״, ״וְגֵר לֹא תִלְחָץ״, ״וְלֹא תִהְיֶה לוֹ כְּנֹשֶׁה״, וְגֵר בַּכְּלָל הוּא! אֶלָּא, אֶחָד זֶה וְאֶחָד זֶה בִּשְׁלֹשָׁה. תַּנְיָא, רַבִּי אֱלִיעֶזֶר הַגָּדוֹל אוֹמֵר: מִפְּנֵי מָה הִזְהִירָה תּוֹרָה בִּשְׁלֹשִׁים וְשִׁשָּׁה מְקוֹמוֹת, וְאָמְרִי לַהּ: בְּאַרְבָּעִים וְשִׁשָּׁה מְקוֹמוֹת, בְּגֵר? מִפְּנֵי שֶׁסּוֹרוֹ רַע.
§ The Sages taught: One who verbally mistreats the convert violates three prohibitions, and one who oppresses him in other ways violates two. The Gemara asks: What is different with regard to verbal mistreatment, that three prohibitions are written concerning it: “And you shall neither mistreat a convert” (Exodus 22:20); “And when a convert lives in your land, you shall not mistreat him” (Leviticus 19:33); “And you shall not mistreat, each man his colleague” (Leviticus 25:17), and a convert is included in the category of colleague? With regard to one who also oppresses a convert as well, three prohibitions are written: “And you shall neither mistreat a convert, nor oppress him” (Exodus 22:20); “And you shall not oppress a convert (Exodus 23:9); “And you shall not be to him like a creditor” (Exodus 22:24). This last prohibition is a general prohibition, in which converts are included. Consequently, it is not correct that one who oppresses a convert violates only two prohibitions. Rather, both this one, who verbally mistreats a convert, and that one, who oppresses him, violate three prohibitions. It is taught in a baraita that Rabbi Eliezer the Great says: For what reason did the Torah issue warnings in thirty-six places, and some say in forty-six places, with regard to causing any distress to a convert? It is due to the fact that a convert’s inclination is evil, i.e., he is prone to return to his previous way of living.