What is the meaning of "v'El Matzor Yerushalayim Tachin Panecha"?
Rashi: When you lie on the left or right, turn your face to the siege of Yerushalayim that you carved on the brick.
Malbim: The brick was on his left as long as he lied on his left, and he faced it, like it said above (3) "va'Hachinosah Es Panecha Eleha."
Why should he bare his arm?
Rashi: This is like one who fights 1 . It is a sign for Nebuchadnetzar, who will fight against it.
Radak citing Targum Yonasan: He told him to clench his arm.
Malbim: This [and prophesizing about it] was only for Yehudah, when he was on his right, for a sign that Hashem put His face towards it and sent His Nevi'im and bared His arm, and constantly prophesized about it via His Nevi'im.
Radak: One who wants to hit and fight strongly, he bares the garment from his arm. This is like "Chashaf Hashem Es Zero'a Kodsho" (Yeshayah 52:10).
What is the significance of having Nevu'ah about it?
Radak: While you besiege it, prophesize about it. Tell it words of Musar, that it will be conquered if it will not repent.
Malbim: Refer to 4:7:2:3.
