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Full story for viewers:
Wonhyo spent the earlier part of his career as a monk. In 661 he and a close friend - Uisang (625–702, founder of the Hwaeom) - were traveling to China where they hoped to study Buddhism further.
Somewhere in the region of Baekje, the pair were caught in a heavy downpour and forced to take shelter in what they believed to be an earthen sanctuary.
During the night Wonhyo was overcome with thirst, and reaching out grasped what he perceived to be a gourd, and drinking from it was refreshed with a draught of cool, refreshing water.
Upon waking the next morning, however, the companions discovered much to their amazement that their shelter was in fact an ancient tomb littered with human skulls, and the vessel from which Wonhyo had drunk was a human skull full of brackish water. Upon seeing this, Wonhyo vomited.
Startled by the experience of believing that a gruesome liquid was a refreshing treat, Wonhyo was astonished at the power of the human mind to transform reality. After this "One Mind" enlightenment experience, he abandoned his plan to go to China. He left the priesthood and turned to the spreading of the Buddhadharma as a layman.
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