Why does it say "Ya'an uv'Ya'an"?
Radak: The repetition strengthens the punishment. The same applies to "Ya'an uv'Ya'an b'Mishpatai Ma'asu" (Vayikra 26:43).
Radak citing Targum Yonasan: Since they prophesized Sheker, and since they deceived My nation.
Malbim: This is punishment amidst punishment, for misleading the people. It is doubled ? it is also for the fruits of their sin.
Why does it say "Hit'u" with a Tes?
Radak: Tes and Tav are interchangeable, for they are pronounced from the same place 1 (the teeth). Everywhere else in Tanach, it is with a Tav, E.g. "Ta'ah Levavi" (Yeshayah 21:4). In the Mishnah and Gemara, it is with a Tes, e.g. v'Hit'u Es Ba'al ha'Bayis (Bava Metzi'a 76b).
Really, no two letters sound the same. However, except for Teimanim, the traditions for the sounds of the letters do not distinguish all letters. (PF)
What is the significance of "Leimor Shalom v'Ein Shalom"?
Radak: Refer to 13:10:4:2.
Malbim: The false Nevi'im promised inner Shalom ? that their way is good, and about external Shalom ? that the enemy will not come against them.
What is the meaning of "v'Hu Boneh Chayitz"?
Rashi: My nation, it is as if they build a wall.
Radak: The false Nevi'im, via their false promises, are like one who built an inferior wall. This is a Mashal ? they say to build Yerushalayim a lasting building.
Malbim: It is a weak wall of sticks.
Malbim (according to the Nimshal): (a) The wall represents that they strengthened the wall of Yerushalayim due to the enemy, and thought that he cannot conquer it. Really, it is a flimsy wall of sticks. With their words, they plaster the wall to make it look strong, but really, it merely is heavy on the wall, and does not last. (b) The wall also represents the iron wall that Hashem put between Him and the city. They put a flimsy wall between them and their G-d ? "Avonoseichem Hayu Mavdilim Beinchem l'Vein Elokeichem" (Yeshayah 59:2). Since one can see through a fence of sticks, through the holes "Metzitz Min ha'Charachim" (Shir ha'Shirim 2:9).
What is "Tafel"?
Rashi: It is an addition.\od laaz
Radak: It is an inferior substance that does not last ? "ha'Ye'achel Tafel mi'Beli Melach" (Iyov 6:6) ? it has no taste.
Radak citing his father: They are bricks that were not fired. A building built from such bricks, when rain comes, it falls.
Malbim: It is thick mud that is heavy on the wall, and does not last.
Who plasters, and what do they plaster?
Rashi: The Nevi'im plaster the metaphorical wall with earth that resembles plaster, but it does not last against rain.
Radak: The false Nevi'im beauty their words with flattery, like one who builds a house and plasters it. So it says below ? "Eretz Lo Metoharah Hi; ? u'Nevi'eha Tachu Lahem Tafel" (22:24, 28).
Malbim: The false Nevi'im] plaster it with Tafel. I.e. they cause Hashgachah to totally depart from them via corrupting the nation.
