Behold, a people shall come from the north, and a great nation, and many kings shall be raised up from the coasts of the earth.
Behold, a people shall come forth from the north ... They shall hold the bow ... The king of Babylon hath heard the report ... - (Compare Jeremiah 6:22-24, where the same expressions are used of the invasion of Judea by the Babylonian king advancing from the north). The very language used to describe the calamities which Babylon inflicted on Zion, is that here employed to describe Babylon's own calamity inflicted by the Medes. Retribution in kind.
Many kings - the allies and satraps of the various provinces of the Medo-Persian empire-Armenia, Hyrcania, Lydia, etc.
Shall be raised up from the coasts of the earth - i:e., from the remote parts of the earth.
Verse 42. They are cruel - the character of the Persians, and even of Cyrus, notwithstanding his wish to be thought magnanimous (Isaiah 3:18).
They shall ride upon horses, every one put in array, like a man - so orderly and united is their "array" that the whole army moves to battle as one man (Grotius).
Verse 43. His hands waxed feeble - attempted no resistance; immediately was overcome, as Herodotus tells us.