What is the meaning of "[b'Evras Hashem] Netam Aretz"?
Rashi citing Targum Yonasan: The land will be scorched 1 .
Rashi: There is nothing like this in Tanach, and not in Targum or another language. I say that via Hashem's anger, the smoke was Netam to the land. This is like Nigzar (was decreed) Al ha'Aretz or Nitach v'Higi'a la'Aretz.
Radak: It will be darkened; this is based on Arabic.
Malbim (17-18): The verse depicts Hashem's anger as a storm wind. It seals the fire and smoke, and brings them down to the land, and the trunks themselves will burn. It is known that if a fire extinguished and the smoke rises to a place where the fire burns, it will ignite also what extinguished below.
Rashi: This is difficult. If so, it should have said Netamah (feminine) ha'Aretz! Radak - sometimes Eretz is masculine, e.g. "Sharatz Artzam Tzfarde'im" (Tehilim 105:30).
What is "k'Ma'acholes Esh"?
Radak, Malbim: It is like a matter consumed in fire. A piece of wood that burned, it lights another piece of wood. So this nation, a man does not have mercy on his brother. The evil that their enemies do to them is not enough - also they do evil to each other.
