Why should they be quiet?
Rashi: In order that they can hear My words. Radak - one who speaks does not hearken [to others' words].
Malbim: After consoling Tziyon, the Navi turns to the nations. He depicts that the redeemer already came. He debates with them to return them to Emunah in unity [of Hashem] and the true creed. One of the four reasons why one is defeated in a debate is if he is small. Therefore, the small islands should be quiet, and Le'umim (big nations) will debate 1 . Also refer to 41:1:3:3, 41:1:4:2, 41:1:6:2.
I.e. there will not be 'external' excuses why the nations will be defeated. (PF)
Who are the "Iyim"?
Rashi: They are nations of Nochrim.
Radak: They are residents of islands.
How will their strength be renewed?
Rashi: They will adorn themselves with all their strength - perhaps they can stand in judgment.
Radak: They will invigorate themselves with claims, if they can answer Me.
Malbim: One reason why one is defeated in a debate is if he did not have time to arrange his claims. Therefore, their strength will be renewed to think and take counsel [what to claim].
Why should they come close?
Radak: In order to hear My words.
Malbim: One reason why one is defeated in a debate is if his opponent is a tyrant or honored; fear of him blocks his ability to claim. Therefore, come close to Me, without fear, and then say all that is in your heart.
When will they speak?
Rashi: After they come close.
Radak: After they hear My words, if they have a claim, they will speak.
Why does it say "Yachdav"?
Radak: I and they will come for Mishpat on My claim and theirs. They diminish My strength and ability, and say that I lack strength to save Yisrael from their hands. They serve idols, which have no power!
Malbim: One reason why one is defeated in a debate is if no judge mediates between them - "Ki Lo Ish Kamoni E'enenu
What is "la'Mishpat Nikravah"?
Rashi: To rebuke them in front of them.
