are they trying to fill the Guff?
According to Jewish mythology, in the Garden of Eden there is a Tree of life or the "Tree of Souls":[1] that blossoms and produces new souls, which fall into the Guf, the "Treasury of Souls". Gabriel reaches into the treasury and takes out the first soul that comes into his hand. Then Lailah, the Angel of Conception, watches over the embryo until it is born.
According to Rabbi Isaac Luria, the trees are resting places for souls, sparrows can see the soul's descent, explaining their joyous chirping. The Tree of Souls produces all the souls that have ever existed, or will ever exist. When the last soul descends, the world will come to an end.[2] According to the Talmud, Yevamot 62a, is that the Messiah will not come until the Guf is emptied of all its souls. In keeping with other Jewish legends that envision souls as bird-like, the Guf is sometimes described as a columbarium, or birdhouse. The mystic significance of the Guf is that each person is important and has a unique role which only he or she, with his or her unique soul, can fulfill. Even a newborn baby brings the Messiah closer simply by being born.