[IULIANUS libro quinto digestorum. ] §1.21.3.prEt si praetor sit is, qui alienam iurisdictionem exsequitur, non tamen pro suo imperio agit, sed pro eo cuius mandatu ius dicit, quotiens partibus eius fungitur.
[JULIANUS, Digest, Book 5.] And even if he who exercises another's jurisdiction is a praetor, nevertheless, whenever he performs the other's duties, he does not act by virtue of his own imperium, but on behalf of him by whose delegation he administers justice.