1)
Who said this?
1.
Rashi: People of Yehudah said and lamented so.
2)
What is the meaning of "Kashal Ko'ach ha'Sabal"?
1.
Rashi: Those who carry the rocks and beams to build the wall, their strength faltered. They lack strength to build, due to the enemies. Malbim ? this is like "Shiv'im Elef Ish Sabal" (Divrei ha'Yamim II, Perek 2).
3)
Why did they say "there is much earth"?
1.
Rashi: There is still much mud to put in the wall. I.e. there is much work to do, and we cannot build, due to fear of the enemies.
2.
Malbim: We cannot build the wall until the carriers clear the earth.


