Jamieson, Fausset and Brown on Jeremiah 46:9

9. Ironical exhortation, as in Jr 46:3. The Egyptians, owing to the heat of their climate and abstinence from animal food, were physically weak, and therefore employed mercenary soldiers.

Ethiopians--Hebrew, Cush: Abyssinia and Nubia.

Libyans--Phut, Mauritania, west of Egypt (compare Ge 10:6).

shield--The Libyans borrowed from Egypt the use of the long shield extending to the feet [Xenophon, Cyropædia, 6 and 7].

Lydians--not the Lydians west of Asia Minor (Ge 10:22; Eze 30:5), but the Ludim, an African nation descended from Egypt (Mizraim) (Ge 10:13; Eze 30:5; Na 3:9).

handle and bend the bow--The employment of two verbs expresses the manner of bending the bow, namely, the foot being pressed on the center, and the hands holding the ends of it.