Xuanzang and his disciples came upon the Motherhood River. Women could get impregnated just from drinking its water. Unaware, Xuanzang and Pigsy drank from the river, and their bellies grew big, which frightened them. Fortunately, a local senior told them that water from a nearby spring could cure them. However, the spring was guarded by a Taoist priest called Immortal Ruyi. The monkey managed to handle the immortal and procure the spring water which cured Xuanzang and Pigsy.
