Why does Sefer Ezra begin with the last two verses of Divrei ha'Yamim?
Malbim (Ezra 1:1): Ezra wrote his Sefer and Divrei ha'Yamim. It is the continuation of Divrei ha'Yamim, which ends with Yirmeyah's Nevu'ah that Yisrael will serve Nebuchadnetzar and his sons until Malchus Paras, and that 70 years after the Churban, Koresh will authorize to build the Beis ha'Mikdash. This is why Ezra begins "uvi'Shnas", with the prefix Vov.
What do we learn from "Koresh Melech Paras Kol Mamlachos ha'Aretz"?
'Rashi': I rule over all kingdoms.
Why did he say "Elokei ha'Shamayim"?
Refer to Ezra 1:2:1:1-2.
How did Hashem command Koresh?
'Rashi', Radak #1, Rashi (Ezra 1:2): Yeshayah already said (44:28) "ha'Omer l'Choresh Ro'i... li'Yrushalayim Tibaneh v'Heichal Tivased."
Radak #2: He aroused his spirit.
Why must the Bayis be in Yerushalayim?
Malbim (Ezra 1:2): That is where He desired to dwell, amidst the nation that serves Him.
Why does it say "bi'Yrushalayim Asher bi'Yhudah"?
'Rashi', Rashi (Ezra 1:2): Yerushalayim is in Medinas Yehudah.
Who said "Mi Bachem..."
'Rashi': This was the announcement.
Why does it say "v'Ya'al"?
'Rashi', Radak: Hashem should help him, and he will ascend.
