Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 257
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 257, with English translation by Maimonides (Rambam).
שלא לעבוד בעבד עברי כעבודת עבד, שנאמר "לֹא תַעֲבֹד בּוֹ עֲבוֹדַת עָבֶד" (ויקרא כה, לט).
Not to have a Hebrew servant perform servile tasks, as [Leviticus 25:39] states: "Do not work him like a slave."