What does the verse teach about "me'Amal Nafsho"?
Rashi: He eats and is satiated from his toil; he does not steal.
Radak: From the toil that he suffered in Galus he will get reward - he will see satiation. I.e. he will see good that will satiate him.
Malbim: His consolation for his toil will not be only via his seed. He himself will see and be satiated, and his Nefesh will rest.
What is the meaning of "b'Daito Yatzdik Tzadik Avdi la'Rabim"?
Rashi: My servant judged Emes for all who came to him for judgment.
Radak: Avdi is Yisrael. It says b'Daito, like "Ki Mal'ah ha'Aretz De'ah Es Hashem" (11:9). My servant Yisrael, who is a Tzadik and knows Hashem, will use his Da'as to make many Goyim righteous - "v'Halchu Amim Rabim v'Amru Lechu v'Na'aleh El Har Hashem El Beis Elokei Yakov v'Yorenu mi'Derachav" (2:3).
Malbim: B'Daito is what he knows himself. He will find satiation and contentment from making the Rabim virtuous - he was Mekadesh ha'Shem in public.
Why does he bear their sins?
Rashi: This is the way of Tzadikim - "Atah u'Vanecha
