18. death--that is, the dead; Hades and its inhabitants (Job 28:22; see on Isa 38:11). Plainly Hezekiah believed in a world of disembodied spirits; his language does not imply what skepticism has drawn from it, but simply that he regarded the disembodied state as one incapable of declaring the praises of God before men, for it is, as regards this world, an unseen land of stillness; "the living" alone can praise God on earth, in reference to which only he is speaking; Isa 57:1, 2 shows that at this time the true view of the blessedness of the righteous dead was held, though not with the full clearness of the Gospel, which "has brought life and immortality to light" (2Ti 1:10).
      hope for thy truth-- (Ps 104:27). Their probation is at an end. They can no longer exercise faith and hope in regard to Thy faithfulness to Thy promises, which are limited to the present state. For "hope" ceases (even in the case of the godly) when sight begins (Ro 8:24, 25); the ungodly have "no hope" (1Th 4:13). Hope in God's truth is one of the grounds of praise to God (Ps 71:14; 119:49). Others translate, "cannot celebrate."

JFB.