Jerome : (Vers. 30 seqq.) But this will be a sign for you: Eat in this year what grows of itself, and in the second year what springs from that; then in the third year sow, reap, plant vineyards, and eat their fruit. The remaining survivors of the house of Judah shall take root downward and bear fruit upward; for out of Jerusalem shall come a remnant, and out of Mount Zion a band of survivors. The zeal of the LORD of hosts will do this. All these things the Prophet speaks through messengers to Hezekiah, what Sennacherib said, what the Lord answered him: now he speaks to him directly, so that he may not doubt the things that were said to come. And for this reason, especially, the words of the prophets had credibility among the people: because they not only remembered things that would happen many centuries in the future, but also things that would happen immediately, and would be fulfilled after a short period of time: and that within two years, the Assyrian king would perish and security would be restored to the city of Jerusalem. This will be, he says, a sign of what I predict will happen, that in this year you will eat what grows naturally. Or according to the Seventy, those things which you harvest first. But in the second year, according to Symmachus, eat from the fruits: or according to the same people, those things which have sprouted from the past crops and fallen to the ground as seed. But in the third year, after the Assyrians have been driven away and the siege has been lifted, sow, reap, and plant vineyards, and eat the fruits of them. Indeed, the remaining fragments of this small city, which are now being surrounded by hostile armies, do not believe that they will escape. They will receive such an abundance and happiness of all things that they will be filled, like a tree firmly rooted in a high mountain, with the thickest of fruits. For the remnants will come forth from Jerusalem and from Mount Zion, and they will fill the land of Judaea, not by their own merit, but by the mercy of God, indeed by the zeal that He has shown towards His wicked people. — Commentary on Isaiah