In keeping with other Jewish legends that envision souls as bird-like, the Guf is sometimes described as a columbarium, or birdhouse.
Even a newborn baby brings the Messiah closer simply by being born.
The peculiar idiom of describing the treasury of souls as a "body" may be connected to the mythic tradition of Adam Kadmon, the primordial man.
Adam Kadmon, God's "original intention" for humanity, was a supernal being, androgynous and macro-cosmic (co-equal in size with the universe).
When this Adam sinned, humanity was demoted to the flesh and blood, bifurcated and mortal creatures we are now.