How do we understand "Ki b'Rov Chachmah Rov Ka'as"?
Nedarim 22b: Had Yisrael not sinned, we would only have received the five Chumashim, and Sefer Yehoshua, which is needed for the boundaries of the tribes in Eretz Yisrael. (Maharsha - much of Nevi'im and Kesuvim recount Hashem's anger over Yisrael's sins. Etz Yosef - if not for Chet ha'Egel, we would have understood everything through the Chumashim, without need for other Seforim.)
Rav Sadya Gaon: One who sins, the more Chachmah that he has, he is punished more 1 .
Rashi: A person relies on his Chachmah, and does not distance from Isur. This angers Hashem. I said, I will increase horses and not return the nation to Egypt. In the end, I returned them. I said, I will increase wives and they will not veer my heart. 2 It is written about me "Nashav Hitu Es Levavo" (Melachim I, 11:4). He relied on his Chachmah - "Ne'um ha'Gever l'Isi'el l'Isi'el v'Uchal 3 " (Mishlei 30:1).
Ibn Ezra: One who understands the world better, amidst his great intellect, has more anger and pain. He does not rejoice over children, for he knows that in the end they will die, in his lifetime or afterwards. He does not rejoice in wealth, for [it can depart] like "v'Of Ye'ofef" (Bereishis 1:20), and it will not help on the day of his downfall. And the day of death is between his eyes [he is always aware of it]!
Ibn Ezra (7:3): With great Chachmah, one gets angry with follies of the world and people - "v'Al Tischakam Yoser Lamah Tishomem" (7:16). He leaves civilization, and dies prematurely. One must weigh his words and matters with scales of Tzedek!
Rashbam: Amidst his Chachmah, he thinks deeply about what he sees. This leads to great anger.
Ri Kara: If a person fills his house with silver and gold amidst his Chachmah, and considers that he will die and others will inherit his property, he gets angry at himself for gathering. He hates all that he toiled Tachas ha'Shamesh.
Rid: With much Chachmah, I understand that there is no gain from this world. My pain and anger increase. All 'Chachmah' in this Sefer is not Chachmah of Torah, rather, of Da'as.
R. Avigdor: Via increasing Chachmah, he forgets what he knew before. This increases anger!
Seforno: The Chachmah of the earlier Chachamim has much anger, for they thought that there is no Supervisor, and no individual below the sphere of the moon lives forever. The Tzadik and Rasha are the same after death.
Metzudas David: He truly understands people's actions. When he sees that they are not good, he gets angry, for they are unlike his desire. Anger damages greatly!
For he is considered Mezid. (PF)
Sanhedrin 21b: It says "Lo Yarbeh Lo Susim v'Lo Yashiv Es ha'Am Mitzraymah?; [v'Lo Yarbeh Lo Nashim]" (Devarim 17:16-17)." And so happened - "va'Tetzei Merkavah mi'Mitzrayim" (Melachim I, 10:29).
Rashi (30:1): He said, Kel is with me - I can increase, and the outcomes that the Torah warned about will not occur.
Why does it say "v'Yosif Da'as Yosif Mach'ov"?
Torah Temimah citing Sukah 42b: If a child can eat a k'Zayis of grain, we must distance from his excrement and urine [in order to say Divrei Kedushah]. For a Gadol, in any case we must distance 1 .
Rav Sadya Gaon: The more that he knows, the greater is his anguish.
Rashbam: This is a repetition. He thinks about Hashem's actions in the world, and cannot understand them, and he gets angry.
R. Avigdor: He adds to what his Da'as can attain. This increases pain.
Seforno: One who has more Chachmah [than the earlier Chachamim], and recognizes that there is an order arranged for a purpose, he is pained over what he considers to be a bad order.
Metzudas David: One who increases Da'as, to understand a matter amidst another matter, he understands what will result from the ruinous deeds. This saddens his heart.
Aruch l'Ner (42b): What is the comparison to Da'as? R. Yehudah says that the Eitz ha'Da'as was wheat (Sanhedrin 70b). A child has Da'as only after eating wheat. When he became Gadol via eating wheat, he increases grief.