Revelation 9:9

As it were breastplates of iron

(ως θωρακας σιδερους). The θωραξ was originally the breast (from the neck to the navel), then the breastplate, only N.T. usage (Revelation 9:9; Revelation 9:17; 1 Thessalonians 5:8; Ephesians 6:14). The armour for the breastplate was usually of iron (σιδερους, Revelation 2:27), but with the locusts it only seemed to be so (ως). However, the scaly backs and flanks of the locusts do resemble coats of mail. "The locusts of the Abyss may be the memories of the past brought home at times of Divine visitation" (Swete).The sound of their wings

(η φωνη των πτερυγων). Graphic picture of the onrush of the swarms of demonic locusts and the hopelessness of resisting them.As the sound of chariots, of many horses rushing to war

(ως φωνη αρματων ιππων πολλων τρεχοντων εις πολεμον). Both metaphors here, the clatter and clangour of the chariot wheels and the prancing of the horses are found in Joel 2:4. Τρεχοντων is present active predicate participle of τρεχω, to run. Cf. 2 Kings 7:6; Jeremiah 47:3.