John Calvin on Isaiah 16:2

2. It shall be as a bird let loose. {Bogus footnote} The Prophet now shows what he meant by the former mockery, that the Moabites ought not at that time to think of sending sacrifices, because they will not be able to provide for their safety in any other way than by leaving their native country. By the metaphor of birds he describes the terror with which they shall be struck, so that they will flee even at the rustling of a leaf. He threatens that the Moabites, who had abused their tranquillity, shall have a trembling and wearisome flight.