Charles Ellicott Commentary Isaiah 30:16

"but ye said, No, for we will flee upon horses; therefore shall ye flee: and, We will ride upon the swift; therefore shall they that pursue you be swift." — Isaiah 30:16 (ASV)

We will flee upon horses. — These were expected as the Egyptian contingent of Judah's forces. With them and the prestige attaching to their fame, the generals and statesmen counted on being able to resist Assyria. Isaiah, with his keen insight into the current disposition of Egypt, tells them that the only use of the horses will be for a more rapid retreat, not for the charge of battle.