Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 193
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 193, with English translation by Maimonides (Rambam).
שלא לאכול כלאי הכרם, שנאמר "פן תקדש, המלאה הזרע אשר תזרע, ותבואת, הכרם" (דברים כב,ט); זה הוא איסור אכילה.
Not to eat mixed species planted in a vineyard, as [Deuteronomy 22:9] states: "...lest the yield of the crops you planted and the fruit of the vineyard shall become forfeit." This refers to a prohibition against eating [such produce].