Where the birds make their nests - Furnishing a home for the birds where they may breed their young. In Psalm 104:12, the birds are introduced as singing among the foliage of trees and shrubs by the water-courses; here they are introduced as having their home in the lofty cedars in places which God had made for them. The word rendered "birds" here is the word which in Psalm 84:3 is translated "sparrow," and which is commonly used to denote "small birds." Compare Leviticus 14:4 (margin), and Leviticus 14:5-7, Leviticus 14:49-53. It is used, however, to denote birds of any kind. See Genesis 7:14; Psalm 8:8; Psalm 11:1; Psalm 148:10.
As for the stork - See the notes at Job 39:13.
The fir trees are her house - Her retreat; her abode. The stork here is used to represent the larger class of birds. The meaning is, that they build their nests among the fir-trees or cypresses. See the notes at Isaiah 14:8; notes at Isaiah 41:19. So Milton says:
"The eagle and the stork
On cliffs and cedar-tops their eyries build."
They build their nests, however, not only on fir and pine trees, but on houses and castles. Dr. Thomson ("Land and the Book," vol. i. p. 504), says of them, "These singular birds do not breed in Syria, but pass over it to Asia Minor, and into Northwestern Europe, where they not only build in fir and pine trees upon the mountains, but also enter cities and villages, and make their nests on houses, castles, and minarets."

Where the birds make their nests - צפרים tsipporim signifies swallows, sparrows, and small birds in general; here opposed to the חסידה chasidah or stork. Perhaps the heron may be understood, which is said to be the first of all birds to build her nest, and she builds it on the very highest trees. The general meaning is, that God has provided shelter and support for the greatest and smallest birds; they are all objects of his providential regard.

Where the birds make their nests,.... As they do in large, tall, spreading trees: not any particular "birds", as the sparrow, to which the Septuagint and Vulgate Latin versions, and Apollinarius, restrain it: but birds in general are intended; and especially such as build in large trees, as before and after mentioned. Jarchi applies it to the Israelites dwelling among the trees in the garden of Eden: and it may be much better applied to the saints dwelling in the churches, among the trees of righteousness, under the shadow of Gospel ordinances; see Ezekiel 17:23.
As for the stork, the fir trees are her house; where she makes her nest, and brings up her young. Kimchi says it is a large bird, and builds its nest in high trees, as in cedars; but the bird which goes by the name of "pelargus" with the Greeks, and of "ciconia" with the Latins, and of "stork" with us, for the most part builds its nest on the tops of towers and temples (w), and the roofs of high houses, and seldom in trees; and when it does, it is in such that are not far from the habitations of men, which it loves to be near: perhaps the reason of its not building on houses in Palestine might be because their roofs were flat and frequented, and therefore built on high trees there, as fir trees and cedars. And Olympiodorus (x) says it does not lay its eggs on the ground, but on high trees; and Michaelis on the text attests, that he himself had seen, in many places in Germany, storks nests on very high and dry oaks. It has its name in Hebrew from a word (y) which signifies "holy", "merciful", and "beneficent"; because of the great care which it takes of its dam when grown old (z): and a like behaviour among men is called piety by the apostle, 1-Timothy 5:4. But in the Chaldee tongue, and so in the Targum, it has its name from its whiteness; for though its wings are black, the feathers of its body are white: and so Virgil (a) describes it as a white bird, and as an enemy to serpents; for which reason the Thessalians forbad the killing them, on pain of banishment (b). It was an unclean bird, according to the ceremonial law, Leviticus 11:19. Good men are called by the same name, holy and beneficent; and though they are unclean by nature, yet Christ, the green fir tree, Hosea 14:8 is the house of their habitation; in him they dwell by faith, who receives sinners, and eats with them, Luke 15:2. It is usual with the Latin poets to call the nests of birds their houses (c).
(w) Vid. Turnebi Adversar. l. 8. c. 18. & Praetorii Disp. Histor. Physic. de Crotalistria, c. 6. Heldelin. in ibid. c. 11. (x) Apud Bachart. Hierozoic. par. 2. l. 2. c. 29. col. 330. (y) a Buxtorf. Lexic. fol. 247. (z) Solinus, c. 53. Aelian. de Animal. l. 3. c. 23. (a) "Candida venit avis longis invisa colubris", Georgic. l. 2. (b) Plutarch. de Iside et Osir. prope finem. (c) "Frondiferasque domos avium", Lucret. l. 1. v. 19. "Antiquasque domos avium", Virgil. Georgic. l. 2. v. 209.