Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 197
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 197, with English translation by Maimonides (Rambam).
שלא לאכול חמץ בפסח, שנאמר "לא ייאכל, חמץ" (שמות יג,ג).
Not to partake of chametz on Pesach, as [Exodus 13:3] states: "Do not eat chametz."