Joel 2:4

The appearance of them [is] as the appearance of horses; and as horsemen, so shall they run.

Ver. 4. The appearance of them is as the appearance of horses, and as horsemen] i.e. the locusts and other insects come on amain; they march with much nimbleness and swiftness. A horse is a warlike creature, full of terror; so swift in service, that the Persians dedicated him to their god, the sun, as the swiftest creature to the swiftest god, ωσπερ το ταχιστον τω ταχυτατω (Pausan.). See Job 41:20 Proverbs 21:31. In Persia they do all almost on horseback; they buy, sell, confer, but especially fight on horseback to this day. So they did of old, and so did the Chaldeans, from whom they took the monarchs. These were horsemen, and not as horsemen; the place, therefore, is properly and principally to be understood of the locusts. Confer Revelation 9:7 .