Negative commandment · Lo Ta’aseh #190 of 613
Not to eat roasted grain from newly grown produce before Pesach
שלא לאכול קלי מן החדש
The verse · Vayikra 23:14
וְלֶחֶם וְקָלִי וְכַרְמֶל לֹא תֹאכְלוּ עַד־עֶצֶם הַיּוֹם הַזֶּה עַד הֲבִיאֲכֶם אֶת־קׇרְבַּן אֱלֹהֵיכֶם חֻקַּת עוֹלָם לְדֹרֹתֵיכֶם בְּכֹל מֹשְׁבֹתֵיכֶם
“And you shall eat neither bread, nor parched corn, nor green ears, until that very day, until you have brought an offering to your God: it shall be a statute for ever throughout your generations in all your dwellings.”
The Rambam’s words
Not to eat roasted grain from newly grown produce before Pesach, as [Leviticus, ibid.] continues: "[Until that day,...] you may not eat... roasted grain..."
שלא לאכול קלי מן החדש, שנאמר "וקלי . . . לא תאכלו" (ויקרא כג,יד).
Where in the Mishneh Torah
Hilchot Forbidden Foods הלכות מאכלות אסורות