Isaiah 40:30 Midrash

וְיִֽעֲפ֥וּ נְעָרִ֖ים וְיִגָ֑עוּ וּבַחוּרִ֖ים כָּשׁ֥וֹל יִכָּשֵֽׁלוּ׃

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