Paul speaks of the authority he has as if it were a land over which he rules, those things over which he has authority as being within the borders or "limits" of his land, and those things not under his authority as being beyond the "limits." (See: [[rc://en/ta/man/translate/figs-metaphor]])
This is an idiom. Alternate translation: "will not boast about things over which we have no authority" or "will boast only about things over which we have authority" (See: [[rc://en/ta/man/translate/figs-idiom]])
Paul speaks of the authority he has as if it were a land over which he rules. Alternate translation: "and you are within the border of our authority" (See: [[rc://en/ta/man/translate/figs-metaphor]])