A judge should keep his jurisdiction within the limits of his commission.

Explanation

(English-origin maxim.) A judge who exceeds the bounds of his commission acts without authority — every judicial officer must stay within the jurisdiction conferred upon him.

Where this applies

• A county judge tries to rule on a federal immigration case and is told he has no authority because immigration falls outside his commission.
• A traffic court judge attempts to decide a murder case, and the ruling is void because murder is beyond the jurisdiction granted to traffic court.
• A state family court judge issues an order regarding a military service member's deployment, and the order is struck down because military matters are outside the court's commission.