From Major McDonald
The Arabians were clad in long cloaks girt about the waist: on the right arm were hung long bows, which bent both ways. The Ethiopians clad in the skins of leopards and lions carried bows formed from the branches of the palm trees and not less than four cubits in length: with these they used short reed arrows pointed with sharpened stones instead of iron the stone used for this purpose is the same that is employed in engraving seals. They have besides pikes, armed with stags horns, the ends of which are sharpened like the head of a dart and also knotted clubs. When they go to battle, they daub one half of the body with gypsum (white) and the other half with red ochre. These Arabians and the Ethiopians inhabiting the country about Egypt were under the command of Arsames Son of Darius and or Artystone daughter of Cyrus and whom all his wives Darius loved most he had an image of her formed of solid gold
Herodotus Book 7 Section 3
It is quite evident that those designated Ethiopians by Herodotus were Arabians as Ethiopia in his time was considered to be Arabia