Avatamsaka Sutra
The book's central metaphor is "Indra's Net". As a scriptural image "Indra's Net" was first mentioned in the Atharva Veda (c. 1000 BCE). In Buddhist philosophy, Indra's Net served as a metaphor in the Avatamsaka Sutra and was further developed by Huayen Buddhism to portray the interconnectedness of everything in the universe.