Charles Ellicott Commentary Isaiah 31:5

"As birds hovering, so will Jehovah of hosts protect Jerusalem; he will protect and deliver [it], he will pass over and preserve [it]." — Isaiah 31:5 (ASV)

As birds flying ...—The picture that follows (Aeschylean, as the former was Homeric; see "Aeschylus, Agamemnon 49-54," though there the point is the wailing of the parent birds over the plundered nest) is, at least, not doubtful in its meaning, whether it is meant as a counterpart or antithesis to what precedes it. The eagles hovering over their nest, and scaring off man or beast that attacked their nestlings, supplied the most vivid image possible of protection. (Compare the image, like, but not the same, in Deuteronomy 32:11.)

Passing over.—The word is the same as that used in connection with the Passover festival, and may perhaps imply a reference to it.