Yuanshi Tianzun
Taoists claim that sacrifices offered to Yuanshi Tianzun by the king predate the Xia dynasty. The surviving archaeological record shows that by the Shang dynasty, the shoulder blades of sacrificed oxen were used to send questions or communication through fire and smoke to the divine realm, a practice known as scapulimancy. The heat would cause the bones to crack and royal diviners would interpret the marks as Yuanshi Tianzun's response to the king. Inscriptions used for divination were buried into special orderly pits while those that were for practice or records were buried in common middens after use. Under Yuanshi Tianzun or his later names, the deity received sacrifices from the ruler of China in every Chinese dynasty annually at a great Temple of Heaven in the imperial capital. Following the principles of Chinese geomancy, this would always be located in the southern quarter of the city. During the ritual, a completely healthy bull would be slaughtered and presented as an animal sacrifice to Yuanshi Tianzun. The Book of Rites states the sacrifice should occur on the "longest day" on a round-mound altar. The altar would have three tiers: the highest for Yuanshi Tianzun and the Son of Heaven; the second-highest for the sun and moon; and the lowest for the natural gods such as the stars, clouds, rain, wind, and thunder.