Her gates are sunk into the ground - So completely destroyed, that one might suppose they had been swallowed up in an abyss.
Her king - The prophet’s lamentation, occupied before chiefly with the buildings of the city and temple, now turns to the people, beginning with their temporal rulers.
The law is no more - The Jewish Law, the Torah, came to an end when it no longer had a local habitation. Its enactments were essentially those not of a universal religion, but of a national religion, and the restoration of the nation with a material temple was indispensable to its continued existence. It was only when elevated to be a universal religion, by being made spiritual, that it could do without ark, temple, and a separate people.
Her prophets also find ... - With the Torah, the special gift of prophecy also ceased, since both were unique to the theocracy; but it was not until the establishment of Christianity that they were finally merged in higher developments of grace.