In Jewish mysticism, the Chamber of Guf (or Guph or even Gup) (Hebrew for "body" or "corpse") also called the Otzar (Hebrew for "treasury") is the Hall of Souls, located in the Seventh Heaven. Every human soul is held to emanate from the Guf. The Talmud teaches that the Messiah will not come until the Guf is emptied of all its souls (Yevamot 62a).
The mystic significance of the Guf is that each person is important and has a unique role which only he, with his unique soul, can fulfill. Even a newborn baby brings the Messiah closer simply by being born.
In keeping with other Jewish legends that envision souls as bird-like, the Guf is sometimes described as a columbarium, or birdhouse. Folklore says sparrows can see the soul's descent and this explains their joyous chirping.