Melt Me Down

The Book of Common Prayer renders Psalm 17:3b as "Melt me down; you will find no impurity in me." What an image! Though I tend to try to avoid the heat that melts, the flames and coals are unavoidable. So my concern has to be what impurities will be revealed. I know I am not free of impurities, so my prayer has to be that the melt down will burn them off. Not what I like but what I do desire.