The significance of objects found in empty coffins during the practice of Shijie in Taoism is deeply rooted in the belief of the liberation of the soul from the physical body. According to Taoist beliefs, Shijie allows an adept to escape the confines of the physical body, achieving a form of spiritual liberation. Objects placed in empty coffins can symbolize this transition and may serve various ritualistic purposes.
From the search results, we can gather that these objects might include items such as mirrors and figurines, which are found in the space between the third and fourth coffins in the Mawangdui tombs. These items could represent offerings to guide or protect the deceased's soul or to symbolize the presence of the deceased in the afterlife.
Furthermore, the practice of leaving an empty seat surrounded by sacrificial objects in tombs has been a funerary custom in China since the Han Dynasty. This suggests that the objects found in empty coffins could be part of a long-standing tradition to honor and remember the deceased.
In summary, the objects found in empty coffins during Shijie are significant as they embody the transition of the soul, serve as offerings or guides in the afterlife, and connect to ancient funerary customs. For more detailed information, you can refer to sources like the Wikipedia page on Shijie (Taoism) and the article "Art in a Ritual Context: Rethinking Mawangdui".