His soul — His appetite or desire is unsatisfied. So — No less unsatisfied and insatiable; they shall be always thirsting after more of your blood.
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.