2 Kings 19:29 - Matthew Poole's English Annotations on the Holy Bible

A sign unto thee, to wit, of the certain accomplishment of the promises here made to thee; that Zion should triumph over this insulting enemy, 2 Kings 19:21; that God would not only preserve the city from his present fury, 2 Kings 19:34, but also that God would bless his people with a durable prosperity, and a happy increase, 2 Kings 19:30,31. And thus it is not only a sign of a short deliverance, which would be past before this sign was fulfilled, (though there are instances of such signs as followed the thing done; as Exodus 3:12 Isaiah 7:14) but of a future mercy, which was to continue long after that sign. And this sign was the more necessary, because otherwise Hezekiah and his people had cause to fear that the Assyrians would be greatly enraged for their shameful repulse, and the destruction of their army, and would quickly recruit their army, and return against them with far greater force and violence. But some affirm that Sennacherib, when he heard of Tirhakah's march against him, of which 2 Kings 19:9, went with his army to meet him, and overthrew him, and the Egyptian who was joined with him, as was noted before; and prosecuted his victory by following them into Egypt and Ethiopia; in the conquest of which he spent two years, in which space the people did eat such things as grew of themselves; and in the third year returned to Jerusalem, intending to besiege it. It is true, it is said, and so the sign went before the thing, (which may be objected against the truth of this relation,)2 Kings 19:9, that when he heard of Tirhakah, he sent messengers to Hezekiah, pretending as if he would forthwith come against him; but it is not said that he did so, nor is it set down what he did with Tirhakah, because the design of the sacred writer was only to write the history of the Jewish nation; not of others, but only with respect to them. In the third year: this was an excellent sign, for it was miraculous; especially considering the waste and havoc which the Assyrians had made in the land; and that the Jews had been forced to retire into their strong hold, and consequently to neglect their tilling, and sowing, and reaping; and yet this year they should have sufficient provision from those fruits of the earth which the Assyrian left; and the second year, which probably was the year of release, in which they might neither sow, nor reap from such fruits as the earth brought forth of its own accord; and so in the third year. Sow ye, and reap, and plant vineyards, and eat the fruits thereof; you shall not sow, and another reap, as lately you did; but you shall enjoy the fruit of your own labours.