And who by fire, who by water
Who in the sunshine, who in the night time
Who by high ordeal, who by common trial
Who in your merry merry month of May
“Who by fire” is a direct quote from the Unetanneh Tokef prayer on which the song is based: 
 … who will die at his predestined time and who before his time;  who by water and who by fire , who by sword and who by beast, who by famine and who by thirst, who by upheaval and who by plague, who by strangling and who by stoning. Who will rest and who will wander, who will live in harmony and who will be harried, who will enjoy tranquility and who will suffer, who will be impoverished and who will be enriched, who will be degraded and who will be exalted. … 
 Death by fire is also perhaps a reference to the burning at the stake of Joan of Arc, to whom he sings  a song  on his previous album.
Who by Fire