Isaiah 31:5

“As birds flying, so will the Lord of hosts defend Jerusalem, &c.] As the preceding metaphor expresses the mighty power of God, this his tenderness and affection, as well as his speed and swiftness in the deliverance of his people. As birds in the air, at a distance, especially the eagle, have their eye upon their nests, and their young ones in them, and when in danger fly to their assistance, and hover over them, and about them, to keep off those that would hurt them, or carry them away; so the Lord, on high, sees his people when in distress, and hastens to help them, and does surround, protect, and defend them: thus the Lord did, when Sennacherib with his army besieged Jerusalem; who…”

“As in the image of "the lion," the point of comparison is the fearless might of Jehovah; so in that of the birds, it is His solicitous affection (Deu 32:11; Psa 91:4; Mat 23:37). flying--Rather, "which defend" their young with their wings; "to fly" is a secondary meaning of the Hebrew word [MAURER]. "Hovering over" to protect their young [G. V. SMITH]. passing over--as the destroying angel passing over, so as to spare the blood-marked houses of the Israelites on the first passover (Exo 12:13, Exo 12:23, Exo 12:27). He passed, or leaped forward [LOWTH], to destroy the enemy and to spare His people.”

“As birds flying - This is another comparison indicating substantially the same thing as the former, that Yahweh would protect Jerusalem. The idea here is, that He would do it in the same manner as birds defend their young by hovering over them, securing them under their wings, and leaping forward, if they are suddenly attacked, to defend them. Our Saviour has used a similar figure to indicate his readiness to have defended and saved the same city Matthew 23:27, and it is possible that he may have had this passage in his eye. The phrase ‘birds flying,’ may denote the “rapidity” with which birds fly to defend their young, and hence, the rapidity with which God would come to defend Jerusalem;…”

“As birds - Which come from above, and so cannot be kept off; which fly swiftly, and engage resolutely, when their young ones are in danger. Passing over - The destroying angel shall pass over Jerusalem. Isaiah 31:8”

“birds: Isa 10:14; Exo 19:4; Deu 32:11; Psa 46:5, Psa 91:4 defending: Psa 37:40 passing: Or rather, as Bp. Lowth renders, "leaping forward," pasoacḣ As the mother bird spreads her wings to cover her young, throws herself before them, and opposes the rapacious bird that assaults them; so shall Jehovah protect, as with a shield, Jerusalem from the enemy, protecting and delivering, springing forward and rescuing her. Exo 12:27 Isaiah 31:6”

“Jehovah suddenly arrests the work of punishment, and the love which the wrath enfolds within itself begins to appear. "Like fluttering birds, so will Jehovah of Hosts screen Jerusalem; screening and delivering, sparing and setting free." The prophet uses the plural, "like fluttering birds," with an object - namely, not so much to represent Jehovah Himself, as the tender care and, as it were, maternal love, into which His leonine fierceness would be changed. This is indicated by the fact, that he attaches the feminine ‛âphōth to the common gender tsippŏrı̄m. The word pâsōăch recals to mind the deliverance from Egypt (as in Isa 30:29) in a very significant manner. The sparing of the…”