What is the meaning of "Yish'u v'Ein Moshi'a"?
Rashi, from Shochar Tov (18:33): They pray to their idols, and hope for salvation, and the idols cannot save them.
Rashi (Shmuel II, 22:42): The verse should be re-arranged. They turn to Hashem, and He does not answer them, and no one saves them. This is like "Yish'eh Adam El Osehu" (Yeshayah 17:7).
Rashi (Shmuel II, 22:42, citing Menachem): This is like "va'Yisha Hashem El Hevel" (Bereishis 4:4); it is an expression of request. It can refer to the one who requests, or the one from whom he requests - "va'Yetar Yitzchak la'Shem... va'Ye'aser Lo Hashem" (Bereishis 25:12). Also here, "Yish'u v'Ein Moshi'a" are the ones who prays, and "va'Yisha Hashem [El Hevel]" is the One to Whom he prayed.
Radak: They look to Hashem, and He does not save them. This is like "v'Lo Sha'u Al Kedosh Yisrael" and "Lo Yish'eh El ha'Mizbechos" (Yeshayah 31:1, 17:8).
Malbim: They request salvation [from people], and no one wages their battle. (The end of the verse says that they request from Hashem, and also He does not answer them.)
Why does Hashem not answer them?
Shochar Tov (18:33): [He will not answer them on the day of judgment when they are afflicted in Gehinom, because they did not repent in their lifetime.
Radak: They are Resha'im. They call to Hashem, but their hearts are not proper with Him.
Perhaps it is because they call to Hashem only after they prayed to their idols, and were not answered, like Rashi writes. (PF)
Why does it say "Al Hashem"?
Radak: This is like El Hashem. Also "v'Nitan ha'Sefer Al Asher Lo Yada Sefer" (Yeshayah 29:12, is like El Asher...)
