Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 67
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 67, with English translation by Maimonides (Rambam).
שלא להשבית שמירה סביב למקדש, שנאמר "וּשְׁמַרְתֶּם אֶת מִשְׁמַרְתִּי" (ויקרא יח, ל).
Not to interrupt the watch held around the Temple, as [Leviticus 18:30] states: "And you shall keep My watch." it appears to be an error, because the passage it introduces deals with sexual offenses. In Sefer HaMitzvot, the Rambam quotes as a prooftext Numbers 18:5, "And you shall keep the watch over the holy articles."