What is the meaning of "Nidmu Ami"?
Radak: They were cut off.
Radak citing Targum Yonasan: They were foolish.
Malbim: My nation are compared to you ? they lack Da'as, like you. They learned from you to despise Da'as!
Why does it say "mi'Beli Da'as"?
Radak: No one informs and shows them the good path. Even though Nevi'im rebuked them every day for their evil, since the Kohanim, who should have taught the Torah to them, strayed from the true path, just like the nation, [the nation] relied on [the Kohanim. The nation] was also unsure about the true Nevi'im, for false Nevi'im instructed them the opposite of the Emes. Therefore the nation was ruined.
Why did Hashem despise you from being Kohen to Him?
Radak: This refers to the Kohen at the time. It is the Kohen's task to teach the nation. You despised Da'as for yourself, and to teach it to the nation. Therefore, I despised you from being Kohen to Me.
Malbim: "Ki Sifsei Chohen Yishemru Da'as v'Sorah Yevakshu mi'Pihu" (Mal'achi 2:7). Since you despised Da'as, you are not proper for Kehunah.
Why did you forget "Toras Elokecha"?
Radak: Kohanim were give to teach them ? "va'Yichtov Moshe Es ha'Torah ha'Zos va'Yitenah El ha'Kohanim Bnei Levi", ? "Yoru Mishpatecha l'Yakov" (Devarim 31:9, 33:10), and you forgot to teach it and instruct them.
Why will Hashem forget your children?
Rashi: Those who stood on Har Sinai gave their children as guarantors for their fathers to guard the Torah.
Radak: You will die, for "I despised you from being Kohen to Me." I will forget and despise also your children ? they will not stand in place of you. They will not have the honor of Kehunah. They will die or be exiled. 'Forgetting' is a Mashal; it is like one who forgets something and does not put his heart to it. Also "ha'Shachach Chanos Kel" (Tehilim 77:10) and "v'Lo Yishkach Es Bris Avosecha" (Devarim 4:31) are like this.
Malbim: You totally forgot the Torah that you knew initially. At first, you remembered the Torah, even though you forgot Da'as Elokim ? then, I did not forget you, for there was hope that your children will go in My Torah ? 'if only they abandoned Me and guarded My Torah ? the light in it would have returned them to Me!' (Eichah Rabah, Peshichah 2). Now that you forgot My Torah, I will forget your children, for there is no hope that a Tzadik will sprout from them 1 .
We find that children of Resha'im became big Tzadikim, e.g. Chizkiyah and Yoshiyah! We can say that their fathers remembered Torah. Achav and Yarav'am were among the most evil kings, and they expounded Torah greatly (Sanhedrin 103b)! (PF)
