Once I put to music a verse of an inspired poet of Persia, and I sang it with great joy for the words had a beautiful meaning; yet at the same time I always felt that the verse had a meaning beyond the apparent one, which I did not understand. I had a distinct feeling that something was sealed and hidden there. And after fifteen years it happened, when my mind was searching for a simile for a certain revelation, that a voice came, bringing it to my mind. There was no end to my joy in opening that seal which had been closed for fifteen years!