Why did He compare Yirmeyah to a fortified city, iron pillar and copper wall?
Radak: They will not be able to overcome you, just like one cannot conquer a fortified city, and all the more so if it has a copper wall. He mentioned an iron pillar, for a person cannot tilt it or break it.
Malbim: Do not say that they will not pay attention to you to stand against you. They will fight you (verse 19), like one attacks a fortified city, iron pillar and copper wall.
What is "Al Kol ha'Aretz"?
Radak: It is like it explains after this - Malchei Yehudah.
Radak citing Targum Yonasan: [To give a cursed cup to drink] to all residents of the land.
What is the meaning of "l'Malchei Yehudah"?
Rashi: It is opposite Malchei Yehudah.
Malbim: Also they will fight you, like one attacks a fortified city
Why did He add "l'Sareha l'Chohaneha"?
Malbim: Not only the haughty kings will fight you - also the officers and Kohanim [will fight you].
