The king, therefore, with pious curiosity, came unto him in the chapel, and, calling him to him, inquired whether he could indeed see. This the man began to affirm and gave thanks to God. To test the truth of the words, however, the king, as pure as a dove, stretched forth the palm of his hand, and asked for an account of his action. "You are stretching out your hand, O my lord king," the man replied.
Once more the king, sticking his forefinger and middle finger like a pair of horns before the man’s face, asked what he did. And the man answered what he saw. Also, a third time, the king, grasping his beard in his hand, again asked what he did. And the man furnished correctly the information that was sought. Then the king considered that he had been sufficiently examined.
The Life of King Edward who rests at Westminster, trans. Frank Barlow, (1992), p.95.
I must confess that the horns and the beard-pulling amuse me.