Why does it say "Shemesh Yare'ach"?
Ibn Ezra (Bereishis 16:12), Radak (ibid. 9:3): It means Shemesh v'Yare'ach; the prefix Vov is omitted.
What is the significance of "Amad Zevulah"?
Sanhedrin 110a: The sun and moon went up to Zevul (a level in Shamayim) and protested to Hashem 'we will not run our course unless you judge Moshe's case (i.e. punish Korach)'. Hashem shot arrows at them. 'You do not protest for My honor (people bow to the sun every day), but you protest for the honor of a person?!' To this day, they only go out after being hit.
Rashi: They stood in their abodes. The suffix Hei is in place of the prefix Lamed. The verse refers to the war against Giv'on, like Targum Yonasan says. Radak - Yehoshua told the sun and moon to stand still, until Yisrael will finish off their enemies ? "va'Ya'amod ha'Shemesh ba'Chatzi ha'Shamayim" Yehoshua 10:12-13). Their place is in Zevul 1 , in Shamayim.
Malbim: The verse depicts that in the war that Hashem will fight with Yisrael's enemies in the future, the sun and moon will stand still, like in the days of Yehoshua. There will fall Avnei Algabish (giant hailstones), like fell on the Kena'anim.
Radak: The Hei in Zevulah is extra, just like the Hei in Laylah, for it is mi'L'eil. (If it was needed, i.e. the word was feminine, the last syllable would be accented. - PF)
Who go via the light of Your arrows?
Refer to 3:11:2:1.
Rashi: Yisrael. Radak ? Yisrael went via the light of lightning bolts and hailstones that Hashem cast on the [enemy 1 ] when they fled Yisrael. Lightning is Hashem's arrows and spear. Even though the verse did not mention lightning, since it mentions hailstones, it is as if it mentions lightning, for hail does not fall without lightning. Hailstones are white, and shine, and give light at night and during the day 2 . The war was at night, for Yehoshua prayed that the moon stand 3 . It was a double miracle ? the moon illuminated at night with the hail 4 .
Malbim: This teaches that the sun and moon did not stop so that Yisrael would go via their light, like it was in the days of Yehoshua. In the future, they will go via the arrows' light. The metaphor is, the sun, moon and Heavenly legions will not function in their orbits ? war is of Hashem; everything will be from Him, without an intermediary.
Our text of Radak says 'Mitzrim' , but this is difficult. We discuss Yehoshua's war against the Kena'anim! At Keri'as Yam Suf, Yisrael went via light of the angel (or cloud) before the Egyptians fled (Shemos 14:20)! We do not find hail at Keri'as Yam Suf! If Radak holds like Abarvenel (Shemos 14:15), that all the Makos were repeated at Yam Suf, he should have said so! Sometimes Chazal said 'Mitzri', and they refer to all Goyim, e.g. 'Ein Av l'Mitzri' (Yevamos 98a). (PF)
Normal hail only reflects light. Perhaps there was fire in the hailstones (like in Makas Barad), therefore they illuminated. (PF)
Surely it was during the day - he told the sun to stand! Perhaps since he commanded also the moon, it must have been close to sunset; also the moon can be visible then. The war continued into the night.
What is miraculous about the moon illuminating at night? And did he not tell the sun to stop so there would be much light, to enable Yisrael to finish off the enemy? Perhaps Radak means that the moon and hail illuminated at night with the sun. (PF)