Shared ground
Isaiah 38:18–20 closes Hezekiah’s reflection by contrasting what can happen in life versus in death. The plain point is not abstract speculation but a practical one: when a person dies and goes to Sheol (“the pit”), they no longer participate in visible, communal praise of God (v.18). In that sense, death is pictured as silence.
Hezekiah presents continued life as the setting where thanks can be voiced “this day” (v.19), and where God’s “truth” can be made known across generations (v.19). The ending frames his recovery as Yahweh’s saving help and looks ahead to sustained, public music in the temple (v.20).
Where interpretation differs (only where needed)
What “your truth” means (vv.18–19). Some take “truth” mainly as God’s reliability—his proven faithfulness and promise-keeping that can be trusted and publicly affirmed. Others take it more as God’s revealed instruction—what is taught about God and his ways. The verses work well with either sense, since Hezekiah links “truth” both to hope (v.18) and to a father telling children (v.19).
What “cannot hope” implies (v.18). Some read it as a statement about the dead having no expectation at all. Others read it as a statement about the dead no longer expressing hope and testimony in the public worshiping community. The surrounding lines (“cannot praise… cannot celebrate”) push the focus toward what death prevents in public, embodied worship.
Who is included in “we will sing” (v.20). “We” could mean Hezekiah with his household/royal court, or it could widen to the worshiping community that joins temple song. Either way, the scene is corporate and temple-centered.
Why the disagreement exists
The passage uses poetic, compressed language about Sheol and about “truth,” and it does not stop to define whether the emphasis is on inner experience after death or on participation in public worship. It also shifts quickly from “I” (Hezekiah) to “we” (temple praise), leaving the group size implied rather than stated.
What this passage clearly contributes
These verses explicitly connect deliverance from death with renewed, public praise of Yahweh (vv.18–20). They also portray family-to-family transmission as a key way God’s “truth” is kept alive in the community (v.19). The text’s emphasis is that embodied life enables thanksgiving, teaching, and ongoing worship in ways death does not (vv.18–19), and that Hezekiah interprets his survival as Yahweh’s readiness to save (v.20).