1)
How will they resemble "Afar Al Pnei Ru'ach?
1.
Malbim: Finely ground earth scatters in every direction - and so the enemy soldiers will flee in every direction.
2)
Why does it say "Arikem"?
1.
Rashi: It will be like mud that pours. It is not thick. This is like "Hem Merikim Sakeihem" (Bereishis 42:35), "v'Lo Hurak mi'Keli El Kli" (Yirmeyah 48:11).
2.
Radak #1: The root is Rekek (mud), mentioned in Chazal, e.g. Chulin 27:2. I will make them muddy.
3.
Radak #2: This is like "Rakos Basar" (Bereishis 41:19, i.e. lean) and "Rekikei Matzos" (Shemos 29:2 - thin wafers).
