Why does it say "he'Amur Beis Yakov"?
Rashi: This is what Beis Yakov say when they hear the evil that My Nevi'im prophesize for them. Radak ? the Hei is the prefix Hei ha'Yedi'ah (to identify). It has a Segol, like "va'Yasar he'Arov" (Shemos 8:27). This calls out to Beis Yakov, like "ha'Kahal Chukah Achas Lachem" (Bamidbar 15:15), "ha'Dor Atem Re'u Devar Hashem" (Yirmeyah 2:31).
Malbim: This is what Beis Yakov regularly say.
What is the question "ha'Katzar Ru'ach Hashem"?
Rashi: Does Hashem not have ability to benefit? Is His spirit not inclined for good, like it was in previous days?
Radak: You, that Beis Yakov tell you "ha'Katzar Ru'ach Hashem", that you tell Hashem's Nevi'im "Al Tatifu" (6) ? is Nevu'as Hashem short for you? Why do you detest it? It was wide (pleasant) for you to rebuke you to improve you, as long as you wanted to hear it. I did not withhold it from you! Ha'Katzar is past tense.
Malbim: Do evil deeds affect Hashem, and He cannot bear them, and therefore He is angry and decrees punishment on the nation?
What is the question "Im Eleh Ma'alalav"?
Rashi: Are His deeds to do evil?
Radak: These afflictions that come upon you ? are they His deeds? No, they are your deeds!
Malbim: If you will say that evil deeds do not affect Him, to be angry at those who transgress His will, are His deeds to do evil to His creations? His deeds are good, Chesed and mercy, and not to decree evil and punishments!
What is the answer "ha'Lo Devarai Yetivu Im ha'Yashar Holech"?
Rashi: My Ru'ach is not Katzar. My deeds are evil only for Resha'im. One who goes straightly, I benefit him!
Radak: My words benefit and do not harm, if man goes in a straight path. Malbim ? therefore, you should rejoice over My words. They are not bad! They are consolation; Nevi'im testify that Hashem oversees people's deeds, to pay man according to his acts. A straight person can hope for Tzedakah and Chesed from Him ? "Simchah la'Tzadik Asos Mishpat" (Mishlei 21:15)!