Isaiah 38:18

For the grave cannot praise thee - The Hebrew word here is sheol. It is put by metonymy here for those who are in the grave, that is, for the dead. The word ‘praise’ here refers evidently to the public and solemn celebration of the goodness of God. It is clear, I think, that Hezekiah had a belief in a future state, or that he expected to dwell with ‘the inhabitants of the land of silence’ Isaiah 38:11 when he died. But he did not regard that state as one adapted to the celebration of the public praises of God. It was a land of darkness; an abode of silence and stillness; a place where there was no temple, and no public praise such as he had been accustomed to. A similar sentiment is expressed by David in Psalms 6:5 :

For in death there is no remembrance of thee;

In the grave who shall give thee thanks?

In regard to the Jewish conceptions of the state of the dead, see the notes at Isaiah 14:15, Isaiah 14:19.

(See the Supplementary note at Isaiah 14:9; also the Prefatory Remarks by the Editor on the Author’s exposition of Job. The ideas entertained by the Author on the state of knowledge among the ancient saints regarding a future world, cannot but be regarded as especially unfortunate. After the fashion of some German critics, the Old Testament worthies are reduced to the same level with the heroes of Homer and Virgil, as far as this matter is concerned at least.)

Cannot hope for thy truth - They are shut out from all the means by which thy truth is brought to the mind, and the offers of salvation are presented. Their probation is at an end; their privileges are closed; their destiny is sealed up. The idea is, it is a privilege to live, because this is a world where the offers of salvation are made, and where those who are conscious of guilt may hope in the mercy of God.