Will they seed Ru'ach?!
Radak: They toil in vain, like one who seeds Ru'ach, which has no substance. He reaps only Ru'ach, or less than this. I.e. he will not get benefit from it at all, only damage.
Malbim: They will be paid like their deeds. Just like they seeded Ru'ach, so they will reap in the end what grew from Ru'ach.
What is "Sufasah"?
Radak: It is worse than Stam Ru'ach (wind). It is a storm wind, like "b'Sufah uvi'S'arah Darko" (Nachum 1:3). The Sav in Sufasah is like the Sav in Yeshu'asah 1 . The matter is repeated to strengthen it.
If a noun ends with a Hei, and the suffix Hei is added, the Hei of the noun becomes a Sav. (PF)
What is the significance of "Kamah Ein Lo"?
Rashi: Their seed will not produce a crop. I.e. their deeds will not succeed. Radak ? because it used a Mashal of seeding it discusses reaping. Also they will not hope for benefit from their deeds.
What is the meaning of "Tzemach Bli Ya'aseh Kemach"?
Radak: I.e. even if their deeds will succeed a little, it will not last. It will not be a lasting benefit, like produce that is reaped and ground.
Malbim: Also something that begins to sprout from their toil, even though it will never make flour, for it is a thin growth blasted via the east wind, strangers will swallow and destroy it immediately, amidst Safek lest it make flour after it grows. Therefore, they will destroy it before it can grow.
Why does it say "Ulai Ya'aseh"?
Rashi: Even if it will make flour?
Malbim: Refer to 8:7:4:2.
What is the meaning of "Zarim Yivla'uhu"?
Rashi: Even if their property will succeed, in the end it will fall to strangers.
Radak: Even if it will happen once that they reach flour, i.e. their property succeeds to the point that they get a little benefit, strangers will swallow it; their benefit will not be complete.
Malbim: Refer to 8:7:4:2.
