Nut is the ancient Egyptian goddess of the sky, and one of the most vivid images in all Egyptian art: a woman arched over the earth on her fingertips and toes, her long body forming the vault of heaven and often spangled with stars. She is the daughter of Shu, the air, and Tefnut, the moisture, and the sister and wife of Geb, the earth. In the cosmogony her father Shu holds her aloft, separating the sky from the earth below and creating the space of air in which life goes on, so that the arch of Nut over the reclining Geb is a picture of the world's basic structure. Each evening Nut was believed to swallow the sun, which passed through her body during the night, to be given birth again from between her thighs at dawn; the same was imagined for the stars.
Nut's funerary role is old and textually dense: spells in both the Pyramid Texts, carved in Old Kingdom royal burial chambers, and the later Coffin Texts call on her to shield the dead with her arms, reassemble their bones, and give birth to them anew into the afterlife, and one spell has the deceased addressed as being given "to your mother Nut in her name of Sarcophagus, she has embraced you in her name of Coffin," a direct identification of the goddess with the burial container itself. This is why her image was so often painted on the inner lid of a coffin or the underside of a sarcophagus lid, positioned so that, once closed, she faced the mummy directly and enclosed the dead within her own starry body, a practice attested across a very long span of Egyptian funerary art.