1)
When will this be?
1.
Rashi: After the land is desolate.
2.
Radak: The verse is reversed. What is now Shamir va'Shayis (it cannot be cultivated due to war), then it will be very valuable, for its fruits will be blessed.
2)
What is "Shamir va'Shayis"?
1.
Ibn Ezra: They are kinds of thorns. This is because Sancheriv's army destroyed the land year after year.
3)
Why will the vineyards be full of thorns?
1.
Rashi: The owners will flee and abandon them. There will be thorns, worms and scorpions.
2.
Malbim: The verse depicts as if the thorns are the owners (due to the great desolation).
