"One day when the Emperor visited Her Majesty’s rooms, we heard that he had taken along the lute called Mumyō and that some of the ladies-in-waiting were strumming it. We went to have a look, but no one was playing. One of our group toyed with the strings and asked what the instrument was called. ‘It’s far too insignificant to have a name,’ said the Empress. Hearing her reply, I was once more reminded what an admirable mistress I served."
What evidence suggests that the author of the passage is a credible source?