When Merlin heard the maiden speak, he sat down at the edge of the spring and asked her who she was. She told him that she had been born in that country, the daughter of a vavasor there, “a noble man,” she said, “who lives in this manor. And who are you, fair, dear friend?” asked the maiden.

“Lady," he said, “I am a wandering apprentice, seeking my master; he used to teach me my trade, which is most praiseworthy.”

“And what trade is that?” she asked.

“In truth, lady,” he said, “he has taught me so well that I could raise a castle right here and have a great many people take refuge inside and others fall upon it from without. And I could do something else just as well: I could walk across that pond without getting my feet wet. And I could make a river flow over there where no water has ever run before.”

Vulgate Merlin