Why does it say "Yosif"?
Radak: It is like Yosef with a Tzeirei. The same applies to "Hineni Yosif Al Yamecha" (38:5). In addition to the evil that I brought against you, I will bring something worse.
Malbim: Since they say that My words are wondrous, covered and hidden, so I will increase to cover everything from them, until they will not understand My words. They should have realized that Hashem's words to the nation are according to the preparation and intellect of the receiver, and not of the Teacher.
What is "Haflei va'Fele"?
Rashi: It is a covering on a covering. This teaches that the loss of Chachmei Yisrael is twice as harsh as Churban Beis ha'Mikdash and all the curses in Ki Savo, about which is written only "v'Hifla 1 Hashem Es Makosecha" (Devarim 28:59). Here there are two expressions of Hafla'ah.
Radak: It is something that will be wondrous in the eyes of one who sees it. This is like "va'Tered Pela'im" (Eichah 1:9).
Shabbos 138b: In the future Torah will be forgotten from Yisrael. "V'Hifla Hashem Es Makosecha" is like "Hineni Yosef Lehafli
How will the Chachamim lose their Chachmah?
Radak #1: Through Galus and relocation. Their Chachmah is only for evil, but not for good (Yirmeyah 4:22).
Radak #2: When evil will come upon them, they will lose their Chachmah; they will not have a counsel or strategy to be saved from it. Their Chachmah will not help them.
Malbim: The Chachmah that is received in the nation about the reasons for Mitzvos and Hashem's straight ways will be lost.
What does "u'Vinas Nevonav Tistatar" add?
Maharsha (Shabbos 138b): "V'Avdah Chachmas Chachamav" refers to revealed Torah; "u'Vinas Nevonav Tistatar" refers to hidden Torah (Kabalah).
Malbim: This is what they understood by themselves.
