Question: Why do Jews sit on low stools during the Jewish mourning period of Shiva?
Do Jews sit on low stools during the Jewish mourning period of Shiva in order to be close to the ground in which the deceased is buried, to be spiritually close to the newly deceased and to accompany him/her during the period of transition?
Answer: Sitting on low stools during Shiva is a way in which Jewish mourners deprive themselves of luxury during mourning. In the Ancient Near East, sitting on floors was a common sign of mourning -- a modest way of externalizing the depth of ones internal sorrow.
While the rabbis put limits and restrictions on other forms of mourning that were common in the ancient world -- tearing out hair, shredding clothes, wearing sackcloth, and pouring ashes over the body -- they did keep the custom refraining from cushioned seating. The Talmud describes how mourners would turn over their beds and sit on the hard wooden slats.
According to Jewish tradition, mourners during Shiva also should not attend to their occupational work, wear leather shoes (another luxury in ancient times), wear cosmetics, shave or cut their hair, or engage in sexual intercourse. Bathing is permissible for hygienic purposes only, not for pleasure.
The custom of sitting on low stools is not connected with being closer to the earth or of symbolically joining the dead in the ground. On the whole, traditional Judaism is quite uncomfortable with any practice that suggests overindulgence in mourning or desire to join the dead. Rather, the rabbis emphasized that mourning is primarily an internal experience, one that is inconsistent with lavish displays of sorrow.
Best wishes,
Rabbi Jeffrey W. Goldwasser

