Isaiah 5:28

“Whose arrows [are] sharp, and all their bows bent, &c.] Ready to shoot their arrows upon any occasion; and which being sharp, penetrated deep, and were deadly. This includes all kind of warlike instruments, with which they should come furnished, and ready prepared to do execution: their horses’ hoofs shall be counted like flint; by those who rode upon them; who knowing how strong and firm they were, and that they were not worn out, nor hurt by the length of the way they came, would not spare to make haste upon them: and their wheels like a whirlwind; that is, the wheels of their chariots, they used in battle, as Aben Ezra, Jarchi, and Kimchi, interpret it; and so the Septuagint and Arabic…”

“bent--ready for battle. hoofs . . . flint--The ancients did not shoe their horses: hence the value of hard hoofs for long marches. wheels--of their chariots. The Assyrian army abounded in cavalry and chariots (Isa 22:6-7; Isa 36:8).”

“Whose arrows are sharp - Bows and arrows were the common instruments of fighting at a distance. Arrows were, of course, made sharp, and usually pointed with iron, for the purpose of penetrating the shields or coats of mail which were used to guard against them. And all their bows bent - All ready for battle. Their horses’ hoofs shall be counted like flint - It is supposed that the ancients did not usually shoe their horses. Hence, a hard, solid hoof would add greatly to the value of a horse. The prophet here means, that their horses would be prepared for any fatigue, or any expedition; see a full description of horses and chariots in Bochart’s “Hieroz.” P. i. lib. ii. ch. viii. ix. And their…”

“Bent - Who are every way furnished and ready for my work, waiting only for my command. Flint - Because they shall not be broken or battered by the length or stonyness and ruggedness of the way. Whirlwind - For the swiftness of their march, and for the force and violence of their chariots in battle. Isaiah 5:29”

“arrows: Psa 45:5, Psa 120:4; Jer 5:16; Eze 21:9-11 their horses': Jdg 5:22; Jer 47:3; Mic 4:13; Nah 2:3, Nah 2:4, Nah 3:2 Isaiah 5:29”

“The prophet then proceeds to describe their weapons and war-chariots. "He whose arrows are sharpened, and all his bows strung; the hoofs of his horses are counted like flint, and his wheels like the whirlwind." In the prophet's view they are coming nearer and nearer. For he sees that they have brought the sharpened arrows in their quivers ( Isa 22:6); and the fact that all their bows are already trodden (namely, as their length was equal to a man's height, by treading upon the string with the left foot, as we may learn from Arrian's Indica), proves that they are near to the goal. The correct reading in Jablonsky (according to Kimchi's Lex. cf., Michlal yofi) is קשּׁתתיו with dagesh dirimens,…”