Malbim: After telling how part of the land quaked, now it discusses the land as a whole. First it moves to and fro, like a drunkard goes from place to place due to the wine. So the land will move by itself via the disasters contained in it.

Rashi: It is a guard's hut atop a tree.

Radak: It is a hut of one who guards a vineyard. He makes his hut on a mountain, and guards all the vineyards from there. It is made of light wood, for it is not fixed. He stays in it only while the grapes are in the vineyards, to guard them. It is called Melonah, because he is Lan (lodges) there also at night. When the wind strikes that Melonah, it moves to and fro. Because it is light, it stands in its shaking and does not collapse. If something heavy weighs on it, it will fall. So the land will make its residents move to and fro, and they will not be able to stand. Their sins will weigh on them, and they will fall to the ground and not rise again.

Malbim: Afterwards, the land will move like a hut, which moves due to an external cause - wind. The Nimshal is, first there will be rebellion and tumult of skirmishes between man and his fellowman within the country. Afterwards, it will shake due to an enemy from outside. Afterwards, its sin will weigh on it from above and it will fall totally like something that moved from its fixed place. If something weighs on it, it will fall below ¹ .