Thanks for reading.
"Therewith [Pellinore] started unto the king's horse and mounted into the saddle, and said, Gramercy, this horse is my own. Well, said the king, thou mayst take my horse by force, but an I might prove thee whether thou were better on horseback or I. -- Well, said the knight, seek me here when thou wilt, and here nigh this well thou shalt find me, and so passed on his way. Then the king sat in a study, and bade his men fetch his horse as fast as ever they might. Right so came by him Merlin like a child of fourteen year of age, and saluted the king, and asked him why he was so pensive. I may well be pensive, said the king, for I have seen the marvellest sight that ever I saw. That know I well, said Merlin, as well as thyself, and of all thy thoughts, but thou art but a fool to take thought, for it will not amend thee. Also I know what thou art, and who was thy father, and of whom thou wert begotten; King Uther Pendragon was thy father, and [post-Bedegraine spoiler]. That is false, said King Arthur, how shouldest thou know it, for thou art not so old of years to know my father? Yes, said Merlin, I know it better than ye or any man living. I will not believe thee, said Arthur, and was wroth with the child. So departed Merlin, and came again in the likeness of an old man of fourscore year of age, whereof the king was right glad, for he seemed to be right wise.
"Then said the old man, Why are ye so sad? I may well be heavy, said Arthur, for many things. Also here was a child, and told me many things that meseemeth he should not know, for he was not of age to know my father. Yes, said the old man, the child told you truth, and more would he have told you an ye would have suffered him. But [post-Bedegraine spoiler]. What are ye, said Arthur, that tell me these tidings? I am Merlin, and I was he in the child's likeness. Ah, said King Arthur, ye are a marvellous man, but I marvel much of thy words that I must die in battle. Marvel not, said Merlin, for it is." Sir Thomas Malory, Le Morte d'Arthur
Arthuriana sources I use or recommend:
Arthuriana - the Journal of Arthurian Studies; the website of the quarterly journal of the North American Branch of the International Arthurian Society.
The Camelot Project at the University of Rochester.
Camelot In Four Colors: A Survey of the Arthurian Legend in Comics
Mystical-WWW - The Arthurian A2Z knowledge Bank which has encyclopedically-arranged entries on the characters of the Arthurian legends.
Le Morte Darthur: Sir Thomas Malory's Book of King Arthur and of his Noble Knights of the Round Table, Volume 1 and Volume 2.