From the early Church Fathers to now.
“He destroyed the high places, and broke the statues in pieces, and cut down the groves, and broke the brazen serpent, which Moses had made: for till that time the children of Israel burnt incense to it: and he called its name Nohestan.”
“A sovereign serves God one way as man, another way as king; he serves him as man by living according to faith, he serves him as king by exerting the necessary strength to sanction laws that command goodness and prohibit its opposite. It was thus that Hezekiah served him by destroying the groves and temples of idols and the high places that had been set up contrary to the commandments of God.”
“But because he goes on to add "of this man's seed God, according to his promise, has raised up to Israel a Savior, Jesus," he indicates that that testimony must have a deeper meaning in the Lord Jesus, who truly does all the will of God the Father, rather than in the great King David, who, even though according to the previous discussion his sins had been remitted and not imputed and also because of the holy penitence mentioned, could not unjustly be said to have been found according to the heart of God. Yet, how did he do all the will of God? Even if he was exceptionally praised when Scripture relates his times and his deeds, he is marked because he did not destroy the high places where the people of God used to sacrifice contrary to the command of God, who had ordered that sacrifices be offered to him only in the tabernacle of the testament, although in these same high places sacrifice is offered to the same God. The king Hezekiah, himself sprung from the seed of David, afterwards destroyed these places, accompanied by the testimony of his great praise.”
“Then there were the miracles ... of the deadly bites of serpents, inflicted as just punishment for sin, and healed when a brazen serpent was raised on a wooden pole in sight of all, so that not only did relief come to an afflicted people but also the destruction of death by death was symbolized by this image of the crucifixion. This serpent was preserved intact in memory of the miracle but afterwards was worshiped as an idol by the unfaithful people until King Hezekiah, religiously using his power in the service of God, destroyed it and thus gained great renown for his piety.”
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.