Deuteronomy 13:14 - Joseph Benson’s Commentary on the Old and New Testaments

Then thou shalt inquire This is meant of the magistrate, to whose office this properly belonged, and of whom he continues to speak in the same manner, thou, Deu 13:15 and Deuteronomy 13:16. The Jewish writers say, the defection of a city was to be tried by the great sanhedrim. If it appeared that they were thrust away to idolatry, they were to send two learned men to admonish them. If they repented, all was well; if not, all Israel was to go up and execute this sentence. Though we do not find this law put in execution, in all the history of the Jewish Church, yet, for neglecting the execution of it on inferior cities, God himself, by the army of the Chaldeans, executed it on Jerusalem, the head city, which was utterly destroyed, and lay in ruins for seventy years.