Negative commandment · Lo Ta’aseh #193 of 613
Not to eat mixed species planted in a vineyard
שלא לאכול כלאי הכרם
The verse · Devarim 22:9
לֹא־תִזְרַע כַּרְמְךָ כִּלְאָיִם פֶּן־תִּקְדַּשׁ הַמְלֵאָה הַזֶּרַע אֲשֶׁר תִּזְרָע וּתְבוּאַת הַכָּרֶם
“Thou shalt not sow thy vineyard with divers seeds: lest the fruit of the seed which thou hast sown, and the fruit of the vineyard, be forfeited.”
The Rambam’s words
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].
שלא לאכול כלאי הכרם, שנאמר "פן תקדש, המלאה הזרע אשר תזרע, ותבואת, הכרם" (דברים כב,ט); זה הוא איסור אכילה.
Why · Sefer HaChinuch #549
To not eat forbidden mixtures of the vineyard
“From the roots of the commandment, [there is a need to] preface: The matter is known that in all of the commandments of the Torah, G-d distances us from a thing according to [the degree] of the stumbling found in it.”
Who & when
“And this prohibition not to derive benefit from forbidden mixtures from the vineyard is practiced in the Land of Israel from Torah writ, and outside of the Land rabbinically.”
Where in the Mishneh Torah
Hilchot Forbidden Foods הלכות מאכלות אסורות