She is hardened against her young ones - The obvious meaning of this passage, which is a fair translation of the Hebrew, is, that the ostrich is destitute of natural affection for her young; or that she treats them as if she had not the usual natural affection manifested in the animal creation. This sentiment also occurs in Lamentations 4:3, "The daughter of my people is become cruel, like the ostriches in the wilderness." This opinion is controverted by Buffon, but seems fully sustained by those who have most attentively observed the habits of the ostrich. Dr. Shaw, as quoted by Paxton, and in Robinson's Calmet, says, "On the least noise or trivial occasion she forsakes her eggs or her young ones, to which perhaps she never returns; or if she does, it may be too late either to restore life to the one, or to preserve the lives of the others." "Agreeable to this account," says Paxton, "the Arabs meet sometimes with whole nests of these eggs undisturbed, some of which are sweet and good, and others addle and corrupted; others again have their young ones of different growths, according to the time it may be presumed they have been forsaken by the dam. They oftener meet a few of the little ones, not bigger than well-grown pullets, half-starved, straggling and moaning about like so many distressed orphans for their mothers."
Her labour is in vain without fear - Herder renders this," In vain is her travail, but she regards it not." The idea in the passage seems to be this; that the ostrich has not that apprehension or provident care for her young which others birds have. It does not mean that she is an animal remarkably bold and courageous, for the contrary is the fact, and she is, according to the Arabian writers, timid to a proverb; but that she has none of the anxious solicitude for her young which others seem to have - the dread that they may be in want, or in danger, which leads them, often at the peril of their own lives, to provide for and defend them.

She is hardened against her young - See before, and the extracts from Dr. Shaw at the end of the chapter, Job 39:30 (note). She neglects her little ones, which are often found half starved, straggling, and moaning about, like so many deserted orphans, for their mother.

She is hardened against her young ones, as though [they were] not hers: her labour is (i) in vain without fear;
(i) If he should take care of them.

She is hardened against her young ones, as though they were not hers,.... Hence said to be cruel, Lamentations 4:3; not against the young ones she hatches, for Aelianus (c) reports her as very tender of her young, and exposing herself to danger for the preservation of them; but being a very forgetful creature, having laid its eggs in the sand, where it leaves them, forgets where it has laid them; and finding other eggs sits on them and hatches them, and regards the young as its own, and is hardened against its true and real young, as not belonging to her;
her labour is in vain without fear; in laying her eggs and leaving them in the dust, without fear of their being crushed and broken, which yet they are, and so her labour is in vain; or her labour in hatching the eggs of others, without any fear or care of their belonging to others, which yet they do, and so she labours in vain.
(c) Ut supra. (Vid. Aelian. l. 4. c. 37.)

On a slight noise she often forsakes her eggs, and returns not, as if she were "hardened towards her young."
her labour--in producing eggs, is in vain, (yet) she has not disquietude (about her young), unlike other birds, who, if one egg and another are taken away, will go on laying till their full number is made up.

The difficulty of הקשׁיח (from קשׁח, Arab. qsḥ, hardened from קשׁה, Arab. qsâ) being used of the hen-ostrich in the masc., may be removed by the pointing הקשׁיח (Ew.); but this alteration is unnecessary, since the Hebr. also uses the masc. for the fem. where it might be regarded as impossible (vid., Job 39:3, and comp. e.g., Isaiah 32:11.). Jeremiah. translates correctly according to the sense: quasi non sint sui, but ל is not directly equivalent to כּ; what is meant is, that by the harshness of her conduct she treats her young as not belonging to her, so that they become strange to her, Ew. 217, d. In Job 39:16 the accentuation varies: in vain (לריק with Rebia mugrasch) is her labour that is devoid of anxiety; or: in vain is her labour (לריק( ruobal r with Tarcha, יגיעהּ with Munach vicarium) without anxiety (on her part); or: in vain is her labour (לריק with Mercha, יגיעה with Rebia mugrasch), yet she is without anxiety. The middle of these renderings (לריק in all of them, like Isaiah 49:4 = לריק, Isaiah 65:23 and freq.) seems to us the most pleasing: the labour of birth and of the brooding undertaken in places where the eggs are put beyond the danger of being crushed, is without result, without the want of success distressing her, since she does not anticipate it, and therefore also takes no measures to prevent it. The eggs that are only just covered with earth, or that lie round about the nest, actually become a prey to the jackals, wild-cats, and other animals; and men can get them for themselves one by one, if they only take care to prevent their footprints being recognised; for if the ostrich observes that its nest is discovered, it tramples upon its own eggs, and makes its nest elsewhere (Schlottm., according to Lichtenstein's Sdafrik. Reise). That it thus abandons its eggs to the danger of being crushed and to plunder, arises, according to Job 39:17, from the fact that God has caused it to forget wisdom, i.e., as Job 39:17 explains, has extinguished in it, deprived it of, the share thereof (ב as Isaiah 53:12, lxx ἐν, as Acts 8:21) which it might have had. It is only one of the stupidities of the ostrich that is made prominent here; the proverbial ahmaq min en-na‛âme, "more foolish than the ostrich," has its origin in more such characteristics. But if the care with which other animals guard their young ones is denied to it, it has in its stead another remarkable characteristic: at the time when (כּעת here followed by an elliptical relative clause, which is clearly possible, just as with בּעת, Job 6:17) it stretches (itself) on high, i.e., it starts up with alacrity from its ease (on the radical signification of המריא = המרה), and hurries forth with a powerful flapping of its wings, half running half flying, it derides the horse and its rider - they do not overtake it, it is the swiftest of all animals; wherefore Arab. '‛dâ mn 'l-dlı̂m ‛zalı̂m, equivalent to delı̂m according to a less exact pronunciation, supra, p. 582, note) and Arab. 'nfr mn 'l-n‛âmt, fleeter than the ostrich, is just as proverbial as the above Arab. 'ḥmq mn 'l-wa‛nat; and "on ostrich's wings" is equivalent to driving along with incomparable swiftness. Moreover, on תּמריא and תּשׂחק, which refer to the female, it is to be observed that she is very anxious, and deserts everything in her fright, while the male ostrich does not forsake his young, and flees no danger.
(Note: We take this remark from Doumas, Horse of the Sahara. The following contribution from Wetzstein only came to hand after the exposition was completed: "The female ostriches are called רננים not from the whirring of their wings when flapped about, but from their piercing screeching cry when defending their eggs against beasts of prey (chiefly hyaenas), or when searching for the male bird. Now they are called rubd, from sing. rubda (instead of rabdâ), from the black colour of their long wing-feathers; for only the male, which is called חיק (pronounce hêtsh), has white. The ostrich-tribe has the name of בּת יענה bat (Arab. bdt 'l-wa‛nat), 'inhabitant of the desert,' because it is only at home in the most lonely parts of the steppe, in perfectly barren deserts. Neshwn the Himjarite, in his 'Shems el-'olm' (MSS in the Royal Library at Berlin, sectio Wetzst. I No. 149, Bd. i.f. 110b), defines the word el-wa‛na by: ארץ ביצא לא תנבת שׁיא, a white (chalky or sandy) district, which brings forth nothing; and the Kms explains it by ארץ צלבּה, a hard (unfruitful) district. In perfect analogy with the Hebr. the Arabic calls the ostrich abu (and umm) es-sahârâ, 'possessor of the sterile deserts.' The name יענים, Lamentations 4:3, is perfectly correct, and corresponds to the form יעלים (steinbocks); the form פעל (Arab. f‛l) is frequently the Nisbe of פעל and פעלה, according to which יען = בּת היענה and יעל = בּת היּעלה, 'inhabitant of the inaccessible rocks.' Hence, says Neshwn (against the non-Semite Firzbdi), wa‛l (יעל and wa‛la) is exclusively the high place of the rocks, and wa‛il (יעל exclusively the steinbock. The most common Arabic name of the ostrich is na‛âme, נעמה, collective na‛âm, from the softness (nu‛ûma, נעוּמה) of its feathers, with which the Arab women (in Damascus frequently) stuff cushions and pillows. Umm thelâthin, 'mother of thirty,' is the name of the female ostrich, because as a rule she lays thirty eggs. The ostrich egg is called in the steppe dahwa, דּחוה (coll. dahû), a word that is certainly very ancient. Nevertheless the Hauranites prefer the word medha, מדחה. A place hollowed out in the ground serves as a nest, which the ostrich likes best to dig in the hot sand, on which account they are very common in the sandy tracts of Ard ed-Dehan (דהנא), between the Shemmar mountains and the Sawd (Chaldaea). Thence at the end of April come the ostrich hunters with their spoil, the hides of the birds together with the feathers, to Syria. Such an unplucked hide is called gizze (גזּה). The hunters inform us that the female sits alone on the nest from early in the day until evening, and from evening until early in the morning with the male, which wanders about throughout the day. The statement that the ostrich does not sit on its eggs, is perhaps based on the fact that the female frequently, and always before the hunters, forsakes the eggs during the first period of brooding. Even. Job 39:14 and Job 39:15 do not say more than this. But when the time of hatching (called el-faqs, פקץ) is near, the hen no longer leaves the eggs. The same observation is also made with regard to the partridge of Palestine (el-hagel, חגל), which has many other characteristics in common with the ostrich.
That the ostrich is accounted stupid (Job 39:17) may arise from the fact, that when the female has been frightened from the eggs she always seeks out the male with a loud cry; she then, as the hunters unanimously assert, brings him forcibly back to the nest (hence its Arabic name zalı̂m, 'the violent one'). During the interval the hunter has buried himself in the sand, and on their arrival, by a good shot often kills both together in the nest. It may also be accounted as stupidity, that, when the wind is calm, instead of flying before the riding hunters, the bird tries to hide itself behind a mound or in the hollows of the ground. But that, when escape is impossible, it is said to try to hide its head in the sand, the hunters regard as an absurdity. If the wind aids it, the fleeing ostrich spreads out the feathers of its tail like a sail, and by constantly steering itself with its extended wings, it escapes its pursuers with ease. The word המריא, Job 39:18, appears to be a hunting expression, and (without an accus. objecti) to describe this spreading out of the feathers, therefore to be perfectly synonymous with the תערישׁ (Arab. t'rı̂š) of the ostrich hunters of the present day. Thus sings the poet Rshid of the hunting race of the Sulubt: 'And the head (of the bride with its loosened locks) resembles the (soft and black) feathers of the ostrich-hen, when she spreads them out (‛arrashannâ). They saw the hunter coming upon them where there was no hiding-place, And stretched their legs as they fled.' The prohibition to eat the ostrich in the Thora (Leviticus 11:16; Deuteronomy 14:15) is perhaps based upon the cruelty of the hunt; for it is with the rarest exceptions always killed only on its eggs. The female, which, as has been said already, does not flee towards the end of the time of brooding, stoops on the approach of the hunter, inclines the head on one side and looks motionless at her enemy. Several Beduins have said to me, that a man must have a hard heart to fire under such circumstances. If the bird is killed, the hunter covers the blood with sand, puts the female again upon the eggs, buries himself at some distance in the sand, and waits till evening, when the male comes, which is now shot likewise, beside the female. The Mosaic law might accordingly have forbidden the hunting of the ostrich from the same feeling of humanity which unmistakeably regulated it in other decisions (as Exodus 23:19; Deuteronomy 22:6., Leviticus 22:28, and freq.).)

Her labour - In laying her eggs is in vain, because she hath not the fear and tender concern for them, which she should have.