Mishneh Torah — Negative Mitzvot מצוות לא תעשה, Chapter 246
The full Hebrew text of Mishneh Torah, Negative Mitzvot, Chapter 246, with English translation by Maimonides (Rambam).
שלא להסיג גבול, שנאמר "לא תסיג גבול ריעך" (דברים יט,יד).
Not to alter land boundaries, as [Deuteronomy 19:14] states: "Do not remove your neighbor's landmark."