Jewish mourning custom draws directly on the layered soul the Kabbalistic sources describe, and Nefesh, the lowest and most closely bound to the body, is held to linger near the grave for a period traditionally counted as the first year after death, while the higher levels are said to depart more quickly toward their source. This belief is offered by some authorities as part of the reasoning behind the graduated structure of Jewish mourning, an intense first week, a lighter first month, and a fuller mourning period extending to a year for a parent, though the practices themselves rest on a wider set of biblical and rabbinic sources than the soul doctrine alone.
Because Nefesh is the level most tied to bodily appetite and instinct, some later ethical and Hasidic writers describe the ongoing recitation of psalms and charitable acts in a mourner's name as work that helps elevate a relative's Nefesh, refining what was most animal and appetite bound in the person now that it can no longer act through a living body.
This practical, mourning centred use of the soul scheme sits alongside its more abstract role in Kabbalistic cosmology, where Nefesh corresponds to the lowest of the Four Worlds; the funerary use treats the same doctrine as something to act on rather than only something to describe.