The full meaning of this statement can be made explicit. Alternate translation: "You must not take land away from your neighbor by moving the markers on the borders of his land" (See: [[rc://en/ta/man/jit/figs-explicit]])
Moses means that when the people have lived in the land for a long time, they should not move the borders that their ancestors made when they first took the land.
Yahweh giving the land to the people of Israel is spoken of as if they were inheriting the land. Alternate translation: "in the land that Yahweh your God is giving to you to possess" (See: [[rc://en/ta/man/jit/figs-metaphor]])