1)
What is the meaning of "Hashem was sitting on his throne"?
1.
Refer to Melachim I, 22:19:1:1.
2)
Who are "Tzva ha'Shamayim Omedim Al Yemino u'Smolo"
1.
'Rashi': They are angels of destruction (some texts ? serving angels). Malbim (Melachim I, 22:19): They represent Sheluchim of Hashem's Hashgachah, ready to fulfill His decree.
3)
Does "Smol" apply to Hashem?! It says "Yemin Hashem Romemah Yemin Hashem Oseh Chayil" (Tehilim 118:16), "Yemincha Hashem Nedari Ko'ach Yemincha Hashem Tir'atz Oyev" (Shemos 15:6)!
1.
Refer to Melachim I, 22:19:4:1-3.


