Why does it say "Ani Hashem"?
Radak: I, Hashem, did all this - I can take you out of Galus.
To whom did Hashem call?
Rashi: To Yeshayah.
Radak: To Yisrael. I will call to you b'Tzedek when it is time to leave.
Why does it say "v'Achzek b'Yadecha"?
Radak: You will not fear when I take you out, for I will hold your hand.
Malbim: Hashem called to Yeshayah, like one who calls to his friend, and takes him by the hand to lead him to his house, and guards him there. The Nimshal is, Hashem made Yeshayah's nature proper for Nevu'ah, helped him prepare himself for it, and guarded him from stumbling [spiritually].
Why does it say "v'Etzarcha"?
Rashi: When I formed you, My intent was that you will return My nation to My Bris, and illuminate for them.
Radak: I will guard you from Goyim, lest they harm you.
What is "li'Vris Olam"?
Radak: For the Kiyum (continued existence) of every nation. The entire world exists due to you! Every Bris is Kiyum. Yisrael is the Kiyum of the nations in two ways. (a) Due to Yisrael, all the nations will have Shalom, like it says about Mashi'ach "v'Diber Shalom la'Goyim" (Zecharyah 9:10), "v'Hochi'ach l'Amim Rabim v'Chitesu Charvosam l'Itim [
What is "l'Or Goyim"?
Rashi: Each Shevet is called a Goy by itself, like it says "Goy 1 v'Kahal Amim [Yihyeh Mimeka]" (Bereishis 35:11).
Radak: It is a light for the nations (for them to learn from) - "v'Halchu Goyim l'Orech" (60:3). The light is the Torah that will come out from Tziyon.
Malbim: You will illuminate (teach) Emunah to Goyim, lest they go in darkness, and they will recognize Hashem's unity.
Hashem said so to Yakov after 11 Shevatim were born; only Binyamin was not born yet.