Why does it say "Kol Asher Yikra b'Shem Hashem"?
Sifri (49): How can someone be called on Hashem's name?! Just like He is called Rachum, you should be Rachum; just like He is called Chanun, also you should be Chanun 1 .
Radak: In the war of Gog and Magog there will be great affliction for Yisrael for a short time - "Chavi Chim'at Rega Ad Ya'avor Za'am" (Yeshayah 26:20). Many from Yisrael will be eradicated; the Kedoshim and those who fear Hashem will escape - "v'Hayah ha'Nish'ar b'Tziyon veha'Nosar bi'Yrushalayim Kadosh Ye'amer Lo Kol ha'Kasuv la'Chayim bi'Yrushalayim" (Yeshayah 4:3). This is only for those who call to Him in truth - "Karov Hashem l'Chol Kore'av l'Chol Asher Yikra'uhu ve'Emes" (Tehilim 145:18).
Malbim: People will recognize Him also via salvation of Tzadikim. Everyone who calls in the name of Hashem will be saved, and the evil will not rule over him.
Lev Eliyahu (Shemos p.75): It does not say 'just like He has mercy, you should have mercy' - rather, just like He is Rachum and Chanun without limit, also you should be Rachum and Chanun without limit, i.e. as much as you can be. This is the difference between doing Chesed and loving Chesed.
It says "Kol Asher Yikra... Ka'asher Amar" - where was this said?
Rashi: "V'Ra'u Kol Amei ha'Aretz Ki Shem Hashem Nikra Alecha" (Devarim 28:10).
Why does it specify "Har Tziyon and Yerushalayim"?
Radak: The nations will ascend to there.
Malbim: There, all will be saved - v'Hayah ha'Nish'ar b'Tziyon... Kol ha'Kasuv la'Chayim bi'Yrushalayim" (Yeshayah 4:3).
What are the "Seridim"?
Rashi: The remnant that He will leave.
Radak: They are those who call to Hashem in Emes; He calls them Avadai and Ohavai.
Malbim: In places other than Har Tziyon and Yerushalayim, some will be saved (refer to 3:5:5:4).
Why does it say "Asher Hashem Korei"?
Rashi, Targum Yonasan: This is an expression of summonsing, like being called to a meal or to the king's labor.
Radak #1: Refer to 3:5:4:2.
Radak #2: Korei is grandeur and honor. The same applies to "Shalishim u'Keru'im" (Yechezkel 23:23), "Keru'ei ha'Edah" (Bamidbar 1:16).
Malbim: It is all who call to Hashem and pray to Him; they will be saved.
