《太平广记·卷四百七十·水族七》
弟子就捧着符走进水潭，就象走在平地上一样，顺着山脚走了几百丈，看见一个大洞穴，里面很明亮，象人间的住房一样。
弟子遂捧符而入，如履平地。循山脚行数百丈，观大穴明莹，如人间之屋室。
The disciple took the talisman and walked into the pool. It was as if he was walking on flat ground. He walked hundreds of feet along the foot of the mountain and saw a large cave. It was very bright inside, just like a human dwelling.