Why does it say "Rechev Elokim Ribosayim Alfei Shin'an"?
Rashi: Also this is part of what Hashem tells them. He mentions the dearness of His nation. Even when Hashem's chariot of 22,000 sharp angels, and Hashem was among them, was revealed to them at Sinai, [their leader ascended and took the Torah - verse 19].
Radak #1: Hashem's chariot, 20,000 [angels], descended to help Yisrael]. This is like "Shamah Hanchas Hashem Giborecha" (Yo'el 4:11). [Also,] thousands of angels called Shinanim [descended].
Radak #2: Some say that Shin'an is like Shenin, i.e. 2,000.
Malbim: After depicting that Hashem rides on this chariot, it depicts His ascent to the height of Har Bashan to expel the enemies from there, as if He ascended there with a horse and a war chariot. You, Rechev Elokim, ascended above; You took a captive and expelled the enemy. Amidst mentioning the chariot, it describes its essence and great number of legions. It has many myriads (10,000's) of mighty officers.
Why does it say "Hashem Vam Sinai ba'Kodesh"?
Rashi: Refer to 68:18:1:1.
Malbim: Hashem already ascended in this chariot on another mountain - Har Sinai. Then He did not go for war, rather, ba'Kodesh. Har Bashan (which He ascended now for war) is in the same Midbar as Har Sinai.
