Thy crowned— Thy princes. The author of the Observations, in order to explain the phrase. Which camp in the hedges in the cold day, remarks, that the locusts in 1724 and 1725, which in the eastern parts of the world made their first appearance towards the latter end of March, and were prodigiously increased in numbers by the middle of April, began in May gradually to disappear, and retired into the Metijiah, and other adjacent places, where they deposited their eggs, which were hatched in June. These swarms put off their nympha state in about one month, and soon after were dispersed. This retiring in May into the Metijiah, a place full of gardens and consequently of hedges or walls, while the rest of the country, used for feeding of cattle and as arable lands, is all open, without any inclosure whatever—may possibly explain the above words of the prophet. The word גדרות gederoth, translated hedges, precisely speaking, seems to mean the walls of a garden. But it may be asked, Can the months of April and May be called the day of cold in these countries? I observe, that the same word is made use of to signify that grateful cooling which Eglon sought, Joshua 3:20 that these gardens are the places to which the people of the Levant retire for cooling; and that in April and May, the time when the locusts appear in Palestine, the people at Aleppo retire to their gardens; as also, that the locusts are brought by hot winds; from all which I am led to think the day of cold should rather have been translated the day of cooling; the time when people first retire to their summer-houses or country-seats. When the sun ariseth, says the prophet, they flee away, that is, (as I suppose, a like expression, James 1:11 is to be understood,) "When the summer advances, they are totally dispersed;" and though the Sea is now supposed by the eastern people to be their common grave, yet, that probably not being known to be the fact in Nahum's time, the prophet says, upon occasion of their disappearing, (speaking according to the received opinion,) that their place is not known where they are. I will only farther remark on this subject, says our author, that, agreeably to their being called by the prophet great locusts, it is observed by some naturalists, that those locusts which appear in such swarms, are larger than the locusts which are seen at other times; and I mention this, because I do not remember to have seen any thing of this sort in the commentators. See Observations, p. 120, &c.
Related Commentaries of Nahum 3:17
17 Thy crowned are as the locusts, and thy captains as the great grasshoppers, which camp in the hedges in the cold day, but when the sun ariseth they flee away, and their place is not known where they are.