The nations shall see and be confounded at all their might: they shall lay their hand upon their mouth, their ears shall be deaf.
The nations shall see - the "marvelous things" (Micah 7:15; Isaiah 26:11, "Lord, when thy hand is lifted up, they will not see: but they shall see").
And be confounded at all their might - having so suddenly proved unavailing; that might wherewith they had thought that there is nothing which they could not effect against God's people. In Isaiah 26:11, "And be ashamed for their envy at the people."
They shall lay ... hand upon their mouth - the gesture of silence (Job 21:5; Job 40:4; Psalms 107:42, "All iniquity shall stop her mouth;" Isaiah 52:15, "The kings shall shut their mouths at him: for that which hath not been told them shall they see"). They shall be struck dumb at Israel's marvelous deliverance, and no longer boast that God's people is destroyed.
Their ears shall be deaf - they shall stand astounded, so as not to hear what shall be said (Grotius). Once they had eagerly drunk in all rumours as so many messages of victories; but then they shall be afraid of hearing them, because they continually fear new disasters, when they see the God of Israel to be so powerful (Calvin). They shall close their ears, so as not to be compelled to hear of Israel's successes.