What is the meaning of the word "sign" in Isaiah 37:30?

Question

Isaiah 37:

30 “This will be the sign for you, Hezekiah:
“This year you will eat what grows by itself,
and the second year what springs from that.
But in the third year sow and reap,
plant vineyards and eat their fruit.

Does this miracle mean that for 2 years, the Israelites did not need to work the fields? Did this serve as a sign to verse 36?

36 Then the angel of the LORD went out and struck down 185,000 men in the camp of the Assyrians. When the people got up the next morning, there were all the dead bodies!

37So Sennacherib king of Assyria broke camp and withdrew. He returned to Nineveh and stayed there.

It seems that the Assyrian threat was dismissed long before the completion of the agricultural sign which lasted 2 to 3 years.

Answer 1

You first ask about the meaning of a word (‘sign’), then you go on to ask about the possible meaning of the sign. So, the word itself has a simple meaning, and the context of chapter 36 shows what it is.

Through the prophet Isaiah, God had foretold the fall of Assyrian king Sennacherib who had heaped ridicule on the God of Israel. Chapter 37 starts with the king of Judah, Hezekiah, tearing his clothes in anguish at that blasphemy, and going into God’s temple to pray about it. Then Isaiah is given a message from God, first, that Sennacherib’s threats would come to naught. This was fulfilled by a report coming to Sennacherib that Tirhakah (the Cushite king of Egypt) had marched out to fight him, so he had to about-turn to deal with that. Of course, he intended to return to crush Jerusalem after dealing with this urgent threat to himself. Hezekiah again went to the temple, to lay down this second written threat before God in prayer, seeking deliverance. Isaiah gave him another message from God about God’s predicted fall of insolent Sennacherib. Then comes “the sign” to Hezekiah.

The sign is an assurance of the people being able to eat food from the land, which was meant to assure them that, “Once more a remnant of the house of Judah will take root below and bear fruit above… (37:32-32).” The literal sign (or assurance) that God would deliver the people and cause them to ‘grow’ as a nation would be in the land providing them food in exceptionally difficult circumstances. The sign was a physically discerned agricultural series of event over three years. As these events happened, the people would grow in confidence (faith) that Sennacherib would be crushed by God and they would be triumphant.

What did this sign mean? Here I quote from the New Living Translation Study Bible notes:

“Because of the Assyrian siege and its destruction of agriculture, the people of Judah would not be able to plant and harvest as usual. The promise that life would resume after the siege assured them that God was with them and would provide as they carried out their everyday activities. They needed to develop their trust in God over a period of three calendar years in the confident expectation (waiting, 30:15, 18) that God’s word would be true. Perhaps the point was that after rescue from the Assyrians, it would be too late in the present year for fall planting. They would have to wait until fall in the second year to plant again, and they would reap their first crop in the spring and summer of the third year.” (page 1161)

So, it was less a case of not needing to work the fields, as being unable to. But – not to worry – God would provide food for them until they could reap the results of their work during the second year in the spring of the third year.

Answer 2

Isa 37:30 is an allusion to Lev 25 and the year of rest every seventh year. See Lev 25:1-11. The Assyrian conquest prevent the usual sowing of the fields and so the Jews had to rely on a miracle of God as was the case in Isa 7:11 & 38:8 (where the word "sign" is used again).

The Cambridge commentary says this:

30. The “sign” of this verse is of the same nature as that of Exodus 3:12, and ch. Isaiah 7:14. It consists of a series of events, in themselves natural, which will attest the fact that all the circumstances of the deliverance had been foreordained by Jehovah, and foretold by His prophet.

Ellicott sums it up this way:

(30) And this shall be a sign unto thee.—The prophet now turns to Hezekiah, and offers, as was his wont (Isaiah 7:11; Isaiah 38:8), a sign within the horizon of the nearer future as the pledge of the fulfilment of a prediction which had a wider range. It was then autumn, probably near the equinox, which was the beginning of a new year. The Assyrian invasion had stopped all tillage in the previous spring, and the people had to rely upon the spontaneous products of the fields. In the year that was about to open they would be still compelled to draw from the same source, but in twelve months’ time the land would be clear of the invaders, and agriculture would resume its normal course, and the fulfilment of this prediction within the appointed limit of time would guarantee that of the wider promise that follows.

On the sign itself, Barnes says this:

Rosenmuller suggests that the two years in which they are mentioned as sustained by the spontaneous productions of the earth were the two years in which Judea had been already ravaged by Sennacherib, and that the third year was the one in which the prophet was now speaking, and that the prediction means that in that very year they would be permitted to sow and reap. In the explanation of the passage, it is to be observed that the word 'sign' is used in a variety of significations. It may be used as an indication of anything unseen Genesis 1:14; or as a military ensign Numbers 2:2; or as a sign of something future, an omen Isaiah 8:18; or as a token, argument, proof Genesis 17:2; Exodus 31:13. It may be used as a sign or token of the truth of a prophecy; that is, when some minor event furnishes a proof that the whole prophecy would be fulfilled Exodus 3:12; 1 Samuel 2:34; 1 Samuel 10:7, 1 Samuel 10:9. Or it may be used as a wonder, a prodigy, a miracle Deuteronomy 4:34; Deuteronomy 6:22.

In the case before us, it seems to mean that, in the events predicted here, Hezekiah would have a token or argument that the land was completely freed from the invasion of Sennacherib.