His soul is empty; his appetite or desire (as the soul is taken, Psalms 41:4, Psalms 78:18, and elsewhere) is unsatisfied. Or, his stomach or body (as the soul is used, Psalms 16:10) is empty. So shall the multitude of all the nations be, that fight against Mount Zion; no less unsatisfied and unsatiable shall the enemies of the Jews be, with all the cruelties which they have committed against you; and they shall be always thirsting after more of your blood, as if they had never tasted any of it.
Related Commentaries of Isaiah 29:8
Isaiah 29:8
8 It shall even be as when an hungry man dreameth, and, behold, he eateth; but he awaketh, and his soul is empty: or as when a thirsty man dreameth, and, behold, he drinketh; but he awaketh, and, behold, he is faint, and his soul hath appetite: so shall the multitude of all the nations be, that fight against mount Zion.