This is a pun on 'sentence' which is a set of words that is complete in itself, typically containing a subject and predicate, conveying a statement, question, exclamation, or command, and consisting of a main clause and sometimes one or more subordinate clauses. But in the context of judge's, 'sentence' can also mean the punishment assigned to a defendant found guilty by a court, or fixed by law for a particular offense.
If a judge loves the sound of his own voice , expect a long sentence .