When swift your grief then tight my arms cling round the threadbare pattern — yours.
And once again I seem to feel the ancient black inquisitors!
Make fast the knot that ties your heart and does not let it burst — I know.
The arrow lodges where the heart throbs with the blood that cannot flow.
Nor look to me who have no words but clasp the pattern that you keep
For I am binding grief again and dare not loose a pulse — to weep.
"Shared" is about taking on another person's sorrow without being able to speak about it. The speaker holds tight to someone who is grieving, and the grief spreads between them. She is gripping the "threadbare pattern," which seems to stand for the worn, familiar shape of the other person's suffering, and she makes it her own. The "ancient black inquisitors" is a stranger, darker image. It suggests that sharing this pain feels like being judged or tormented, as if something old and merciless has come back.
Most of the poem is a kind of instruction to the grieving person: keep the knot tied, don't let your heart burst. The speaker knows the wound firsthand, an arrow lodged where blood "cannot flow." By the end she has no words to offer, only a refusal to let go. She is binding her own grief too tightly to weep.
The mood is tense and held-in, with sympathy that turns into shared, silent pain.