Here is a quiet, compressed picture of a couple resting together after sex. The speaker and a woman lie motionless, she on top of him, so still they resemble effigies, the carved figures that lie on old tombs. That comparison is odd and a little eerie, but it doesn't feel grim. It suggests a stillness so complete that the two seem sculpted, even sacred.
The "great whispering" and the quick hush suggest murmured talk that fades into contentment. "Satisfied" is the key feeling: nothing is missing. The phrase "vice-tested" hints that the pair have known each other's faults or indulgences and have come through them, and the verb "sup" turns the moment into a small meal, as if they are feeding on each other's company. The "master bed" adds a note of ownership and ceremony, which fits the title, "Rite." The mood is hushed, intimate, and calm, with a faint religious solemnity.