What is the meaning of "Asher ha'Misbarech ba'Aretz"?
Rashi: It is one who glorifies himself.
Radak: It is one who seeks a Brachah for himself, like "v'Hisbarachu v'Zar'acha" (Bereishis 22:18).
Malbim: One who be blessed with any success in the world.
Why does it say "ha'Misbarech ba'Aretz Yisbarech bei'Lokei Amen [veha'Nishba ba'Aretz Yishava bei'Lokei Amen]"?
Rashi: Fear of Me will be on everyone, and the land will be full of knowledge. People will glorify themselves that they are servants of Elokei Amen.
Radak: People will bless themselves and swear 1 in Elokei Amen, for there will be only one belief in the world - in Elokei Amen. They will say 'Elokei Amen should bless me, like He blessed Tzadikim Ploni and Ploni.'
Malbim: Hashem will be the source of all Brachos and success 2 . People will no longer swear in the name of the Resha'im, rather, in Elokei Amen.
What is "Elokei Amen"?
Rashi: It is Elokei Emes, who guarded and Imen (made true) this promise.
Radak: This is like "Kel Emunah v'Ein Avel" (Devarim 32:4) - "Ki Az Ehpoch El Amim Safah Berurah Likro Kulam b'Shem Hashem Le'avdo Shechem Echad" (Tzefanyah 3:9).
Why does it say "Ki Nishkechu Tzaros ha'Rishonos"?
Rashi: This is why they will call Me Elokei Amen.
Radak: Until that time, the world was not without afflictions and wars. Then there will be Shalom in the world - "v'Diber Shalom la'Goyim" (Zecharyah 9:10), "v'Chitesu Charvosam l'Itim va'Chanisoheihem l'Mazmeros Lo Yisa Goy El Goy Cherev v'Lo Yilmedu Od Milchamah" (above, 2:4). There will be so much Shalom that the first afflictions will be forgotten.
Malbim: It will not be feasible to swear in the name of afflictions, for there will be no memory of them.
Why does it add "v'Chi Nisteru me'Einai"?
Radak: He showed that everything was from Hashem, to every nation; it was not chance. And so the Nevi'im spoke about the affliction and wars that will come on every nation, before they came.
Malbim: Until now, afflictions were opposite My eyes, to reward Tzadikim who suffered afflictions without reason. Then they will be hidden also from My eyes, for each already received his reward and punishment, and there will be no memory of past evil at all.