What is the meaning of "k'Chocham"?
Rashi: According to their strength and wealth.
Ibn Ezra: This refers to the Kahal. Refer to 2:69:2:1.
Here it says that Roshei ha'Avos gave 60,000 Darkemonim and 5,000 Manos [of silver]. In Nechemyah 7:70-71, it says 20,000 Darkemonim and 2,200 Manos, and the Am gave 20,000 Darkemonim and 2,000 Manos!
Ibn Ezra: There discusses what the Avos gave. Here it includes the Avos and the rest of the Kahal, and others who volunteered from Koresh's kingdom 1 .
Malbim (Nechemyah 7:70) #1: They gave Nedavos twice. Here discusses those who ascended from Bavel, and Nechemyah includes those who came from the entire Medinah. The latter time, also the Am and ha'Tirshasa gave.
Malbim (Nechemyah 7:70) #2: In the days of Nechemyah, additional Roshei ha'Avos, i.e. those written in the Sefer Yichus that he found, gave.
Malbim (Nechemyah 7:70) #3: Nechemyah discusses a totally new Nedavah. It does not include what is written here.
The total amount in Nechemyah is 20,000 Darkemonim and 800 Manos less than it says here! Ibn Ezra answers that here includes also from others in Koresh's kingdom. (PF)
What are "Darkemonim"?
Rashi: They are gold coins.
What are Manim?
Ibn Ezra: They are weights, like "ha'Maneh Yihyeh Lachem" (Yechezkel 45:12). The Targum of "Shiv'ah Shekalim" (Yirmeyah 32:9) is Shiv'ah Manan.
Why does it mention Kasnos Kohanim?
Rashi: They are to serve in them.
