פּירוש אויף ישעיהו 40:30

“Your youths may grow faint and weary, etc.” [40:30]. The Holy One causes the enemies of Israel to grow tired and empty of commandments. And the youths, that is to say, the nations who were strong like a young man. These same ones will have their strength taken away and they will stumble.⁴Rashi, Isaiah, 40:30.

Now youths shall become tired Heb. נְעָרִים. The might of your enemies who are devoid (מְנֹעָרִים) of commandments, shall become faint.

Even the youths who have strength, faint, etc.

and young men shall stumble Those who are now mighty and strong, shall stumble, but you, who put your hope in the Lord shall gain new strength and power.