佛即法界．眾像影現－北朝至隋代的「法界佛像」=The Buddha as the Dharmadhatu in which all Phenomena Appear: The Buddha Statues of the Dharmadthatu from the Northern Dynasty to the Sui Dynasty
Since the Northern Dynasty, the Buddha statues of the Dharmadhatu decorated with complex images such as the World of Sumeru, Five Realms of sentient beings, and Buddha Shakyamuni's biography have emerged. Various expressions of these images appeared in the beginning until the Tang Dynasty, when the Mt. Sumeru painted on the chest area, this style became prevalent. The Dharmadhatu's original meaning is ''the world'', but this term transformed into other meanings such as the Buddha, and the Pure Land as shown in the inscriptions in the Western and the Eastern Wei Dynasties. Similar usages could also be seen in Mahayana Sutras such as the Huayan, Lotus, and the Mahāsaṃnipāta Sūtras. Whereas in the shastras of the Dilun School that expounded the idea of "the Buddha as the Dharmadhatu", the Dharmadhatu not only referred to the world, but also to the beings other than the three realms. This was the reason why the Buddha's biography, jataka stories, and Bodhisattvas were also depicted on these Buddha Statues of the Dharmadthatu. The imagery of the "non-duality of the Buddha and the Dharmadhatu" was further elaborated and embodied by the Indra Net and the images on the mirrors. All the images shown on the Buddha could be seen as innovations for illuminating the "non-duality of the Buddha and the Dharmadhatu." Not confined to the discourse of Dilun School, the concept of "non-duality of the Buddha and the Dharmadhatu" was also taught by masters from the Northern Dynasty to the Sui Dynasty. Master Zhi Yi said, "the Dharmadhatu does not only appear in the Huayan (Sutras)." Therefore, it is not difficult to understand why images of "the Buddha of Dharmadhatu" became widespread and Mt. Sumeru has been the indispensable element of those images.
