לָכֵ֗ן הִרְחִ֤יבָה שְּׁאוֹל֙ נַפְשָׁ֔הּ וּפָעֲרָ֥ה פִ֖יהָ לִבְלִי־חֹ֑ק וְיָרַ֨ד הֲדָרָ֧הּ וַהֲמוֹנָ֛הּ וּשְׁאוֹנָ֖הּ וְעָלֵ֥ז בָּֽהּ׃
Therefore the nether-world hath enlarged her desire, And opened her mouth without measure; And down goeth their glory, and their tumult, and their uproar, And he that rejoiceth among them.
Rashi on Isaiah
Therefore, the nether-world has expanded Retribution corresponding to deed; they expanded themselves to swallow much food and drink, and they opened their mouth to swallow, so will the nether world expand itself to swallow.
Ibn Ezra on Isaiah
נפשה Her breath.25A. V., Herself. נפש is the breath that comes out of the mouth; comp. נפשו his breath (Job 41:21).