Shall be seen over them— Leading them on and protecting them, as when they came out of Egypt. Exodus 13:21.
His arrow shall go forth as the lightning— The lightnings are represented as the arrows of the Almighty, Psalms 18:14; Psalms 77:17 and he is here said to go forth like the lightning, scattering and discomfiting all before him.
Whirlwinds of the south— The most vehement storms, to which Judaea was subject, came from the great desert country to the south of it.