Albert Barnes on Luke 12:14

Who made me a judge? It is not my business to settle controversies of this kind. They are to be settled by the magistrate. Jesus came for another purpose--to preach the gospel, and so to bring men to a willingness to do right. Civil affairs are to be left to the magistrate. There is no doubt that Jesus could have told him what was right in this case, but then it would have been interfering with the proper office of the magistrates; it might have led him into controversy with the Jews; and it was, besides, evidently apart from the proper business of his life. We may remark, also, that the appropriate business of ministers of the gospel is to attend to spiritual concerns. They should have little to do with the temporal matters of the people. If they can persuade men who are at variance to be reconciled, it is right; but they have no power to take the place of a magistrate, and to settle contentions in a legal way.

(n) "Man, who made me a judge" Jn 18:25