"I'm still a cigarette softly smoking on the edge of a metal ashtray
I begged this place to let me burn, and it whispered, "burn away"
is that his life is like a cigarrette, because it doesn't move a long smoothly, it burns to ashes until it goes out. And he's so miserable that all he asks is to be allowed to continue burning, and this prison or government that he works for acts like that's some big priveledge. This is ultimately why he has to kill Keziah, to keep his family fed.
I believe what the guard means by
"I'm still a cigarette softly smoking on the edge of a metal ashtray I begged this place to let me burn, and it whispered, "burn away"
is that his life is like a cigarrette, because it doesn't move a long smoothly, it burns to ashes until it goes out. And he's so miserable that all he asks is to be allowed to continue burning, and this prison or government that he works for acts like that's some big priveledge. This is ultimately why he has to kill Keziah, to keep his family fed.