Cush and Egypt were her boundless strength; Put and Libya were her allies.
Nineveh has been told that God is against her, and then none can be for her, to stand her in any stead; yet she sets God himself at defiance, and his power and justice, and says, I shall have peace. Threatened folks live long; therefore here the prophet largely shows how vain her confidences would prove and insufficient to ward off the judgment of God.
Commenting on Nahum 3:8-19
Ethiopia and Egypt were her strength,.... That is, the strength, support, protection, and defence of No, whether Alexandria, or Thebes, or Memphis: Egypt was, for these cities were in it, and subject to it; or, if this was a free city, as some think, yet in alliance with Egypt, and under its protection; and in like connection it was with Ethiopia, that is, Arabia, a...
Ethiopia--Hebrew, Cush. Ethiopia is thought at this time to have been mistress of Upper Egypt. Egypt--Lower Egypt. her strength--her safeguard as an ally. it was infinite--The resources of these, her allies, were endless. Put--or Phut (Gen 10:6); descended from Ham (Eze 27:10). From a root meaning a bow; as they were famed as archers [GESENIUS]. Probably west of Lower Egypt.