Lyric discussion by StarkRavenMad 

Cover art for Ashes lyrics by Rufus Wainwright

I think in this song he is reflecting on a past relationship. I think it may have been the first time he felt truly in love, or he may just now be realizing he was in fact, in love with this person. "and I do believe I saw your true love burning next to me. But now there's ashes." They had a burning passion for each other, but the flame has died away and all that's left now are the ashes of what they once had together.