Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 255
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 255, with English translation by Maimonides (Rambam).
שלא להונות עבד זה, שנאמר "עִמְּךָ יֵשֵׁב בְּקִרְבֶּךָ... בַּטּוֹב לוֹ לֹא תּוֹנֶנּוּ" (דברים כג, יז).
Not to wrong such a servant, as [Deuteronomy 23:17] states: "He shall dwell in your midst, in the place which he selects... as he sees fit. Do not wrong him."