“Did you ever learn who the man was who told you about your mother?”

“No,” said Gawainet.

Then Doon began to think about who it could have been, and he started to smile. And when Gawainet saw him, he wondered why he had asked him, and he begged him, in the name of his lord the king, to tell him why he had smiled
and why he had asked him those things. And Doon said to him, “Gawainet, Gawainet, you have asked me repeatedly, I must tell you. But be careful to tell no one else what I am about to say to you.”

And Gawainet said that he would sooner have his
tongue cut out.

“Now you can know,” said Doon, “that the man who brought you the news is called Merlin, and he is the best seer there ever was or ever will be."

Vulgate Merlin