The speaker seems to be in the grip of grief, caught in a state where nothing quite works: they can't sleep, and they can't properly wake. The poem opens with a strange, physical image of the speaker searching their own ears for "clear words," as if language has to be sorted out from the body's noise, without "spittle or rattle." That suggests a wish for something plain and clean to say, and a fear of only managing something choked or broken.
The middle lines carry the central tension. With eyes "shut like a stone" and lips working, the speaker struggles with a demand to give thanks even as life feels more unthankful. The poem doesn't resolve this. It sits in the contradiction. The closing image, a "little blue chamber of grief," feels small, cold and enclosed. The mood is hushed, heavy and suspended, like a long night that never turns into morning. The title's "slant of light" hints at a faint, oblique glimmer, though the poem itself stays mostly in the dark.