What is the significance that their arrows are sharpened?
Radak: All their weapons are ready for war. Also their bows are drawn - when they want to fight, there will be no delay.
Malbim: There will not be any delay, even to sharpen their arrows. Their bows will be drawn by themselves!
What is "ka'Tzar"?
Rashi citing Targum Yonasan: K'Nitara (like a rock).
Radak: It is a strong (Malbim - flint) rock. Their feet will not hurt due to the journey; they will not need to make iron [horseshoes] for them 1 .
Malbim: This shows the success that they will have on the road.
What are "Galgilav"?
Rashi: The wheels of their chariots.
What is "ka'Sufah"?
Radak: It is straw that rolls in the wind. It is an exaggeration for how fast they will come.
Malbim: (It is a whirlwind.) The horses will not need to pull the chariots - the wind will carry them!
