This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Fazang was born in Chang'an of Sogdian family origin, a documented foreign ancestry distinct from a Huayan patriarch descended from an established Chinese lineage native to the Tang capital. That background placed him, from birth, inside the cosmopolitan mix of peoples that filled Chang'an during the Tang dynasty, a documented setting distinct from a monk formed in a single ethnically uniform community.
Fazang articulated the doctrine of shishi wu'ai, the unobstructed mutual interpenetration of all particular phenomena, through the image of Indra's net, a cosmic web hung with a jewel at every knot, each jewel reflecting every other jewel in the net at once, a documented theoretical image distinct from the physical lion and mirrors demonstration he later staged for Empress Wu. Where that demonstration used furniture to make interpenetration vivid for a single audience, Indra's net stated the same doctrine directly in words, drawn from a much older strand of Buddhist cosmological imagery, a documented inherited source distinct from a metaphor original to Fazang himself.
That a monk of Sogdian descent, raised inside Tang China's most cosmopolitan city, reached for a net of endlessly reflecting jewels to state in words the same interpenetration he later built out of an actual lion and an actual room of mirrors, marks Fazang's own use of Indra's net as a documented case where a foreign born philosopher grounded his central Chinese Buddhist doctrine in an image inherited from Buddhism's own older cosmological tradition.