What is the significance of "Shavti li'Yrushalayim b'Rachamim"?
Malbim: Therefore I needed to return to Yerushalayim. Even though now is not the time of the future Ge'ulah, I do so amidst mercy, due to their poverty and affliction.
What do we learn from "Beisi Yibaneh Bah"?
Malbim: The Bayis will be a place for them to pray and fix their deeds, and bring eternal Tzedek if they merit.
What line will be stretched?
Rashi: It is to measure the length and width of the walls.
Radak: It is like a builder's plumb-line.
Malbim: At that time they had permission only to build the Bayis, but not the walls of Yerushalayim, until the 20th year of Artachshasta via Nechemyah. Even so, a line will be stretched to build also the wall.
It is written Kave with a Hei, like the grammatical form of Nave. It is pronounced Kav, without a Hei!
Radak: The pronunciation is like a builder's plumb-line. Malbim ? the Kesiv is like Tikvah ? from now they have hope that the anger will end, if they will fix their deeds.