It's a bit of the very last verse from Paradiso- Dante's Paradise. 'My will and my desire were turned by love, the love that moves the sun and the other stars.' Dante was trying to explain faith, I thnk, as an overpowering love, and maybe it's blasphemous, but that's how I think of the way that I love you. You came into my life and suddenly I had one truth to hold on to- that I loved you, and you loved me.

Cassandra Clare: The Mortal Instrument Series (4 books) (ed. Simon and Schuster, 2011) - ISBN: 9781442440432