Isaiah 40:30 KJV

Even the youths shall faint and be weary, and the young men shall utterly fall:

Isaiah 40:27–31The people of God are reproved for their unbelief and distrust of God. Let them remember they took the names Jacob and Israel, from one who found God...

Psalms 33:16 There is no king saved by the multitude of an host: a mighty man is not delivered by much strength.
Isaiah 13:18 Their bows also shall dash the young men to pieces; and they shall have no pity on the fruit of the womb; their eye shall not spare children.
Amos 2:14 Therefore the flight shall perish from the swift, and the strong shall not strengthen his force, neither shall the mighty deliver himself:
Ecclesiastes 9:11 I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all.
Isaiah 9:17 Therefore the Lord shall have no joy in their young men, neither shall have mercy on their fatherless and widows: for every one is an hypocrite and an evildoer, and every mouth speaketh folly. For all this his anger is not turned away, but his hand is stretched out still.

From OpenBible.info, most relevant first.

Timeline of the Bible808–698 BC · Isaiah, in the days of Uzziah, Jotham, Ahaz, and Hezekiah

Even the youths נְעָרִים nĕʿārîm נַעַר Noun · masculine plural
shall faint וְיִעֲפוּ wĕyiʿăpû יָעַף Verb · qal imperfect, third person masculine plural · with and
and be weary וְיִגָעוּ wĕyigāʿû יָגַע Verb · qal imperfect, third person masculine plural · with and
and the young men וּבַחוּרִים ûbaḥûrîm בָּחוּר Noun · masculine plural · with and
shall utterly כָּשׁוֹל kāšôl כָּשַׁל Verb · qal infinitive absolute
fall יִכָּשֵׁלוּ yikkāšēlû כָּשַׁל Verb · niphal imperfect, third person masculine plural

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