Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 265
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 265, with English translation by Maimonides (Rambam).
שלא לחמוד, שנאמר "לֹא תַחְמֹד אֵשֶׁת רֵעֶךָ" (שמות כ, יג).
Not to covet, as [Exodus 20:14] states: "Do not be envious of your neighbor's wife."