Isaiah 10:18Meaning & Commentary from the Church Fathers

On that day, as he proclaims, referring to that moment, both the mountains and the hills, as well as the oaks and forests, will vanish from existence, impacting both the soul and the flesh. The Assyrian army and its leaders are compared to these lofty formations, as they loomed over others like mountainous peaks. However, they will ultimately fade away; that is, although they seemed vibrant and formidable, they will be stripped of their vitality against their desires. This is reflected in the phrase - will be extinguished; since death will confront them, in a sense, eradicating both their spirit and physical form. It is clear to all that the souls will be consumed alongside the bodies. Through these expressions, He references the might of divine wrath.

After the Lord of hosts has brought shame upon the dignity of the Assyrian prince and kindled a consuming fire upon his head, and once the Light of Israel has been subjected to the inferno of the Assyrian, he, lacking the sanctity of this Divine Light, must find purification through the flames that cleanse, akin to hay. Following this destruction of the very essence that ignites the chastising blaze, the Prophet declares that the mountains, hills, and oaks shall cease their burning, and the fiery conflagration shall be quenched. The scorching fire that consumes and reveals all, starting from the spirit and extending to the body, will be extinguished.

Just as the forest and Carmel, the wooded mountain of Galilee, are destined to be consumed when fire is set upon them, the entire splendor of the Assyrian will be annihilated from spirit to flesh. In terror, like a squirming and timid serpent, he tries to flee from the approaching judgment. What we interpret as the glory of his forest and of his Carmel is rendered as the mountains, hills, and oaks shall be extinguished—implying that all the magnificence and arrogance of the Assyrians, along with their vast number, shall be brought low and humbled.

When we consider the downfall of the Assyrian forces, the mountains and hills symbolize the high-ranking leaders, while the oak trees represent the common soldiers, whose numbers and organized formations resemble a dense forest. All of this will be consumed by the fiery breath of God’s wrath and reduced to ashes. This fire will reach down from the soul to the body, annihilating the entire Assyrian army, comprised of the hardened masses and the rulers who oversee them, akin to the very essence of their being. They will face destruction at the hands of God’s fury, much like straw is devoured by flames.