Next rifle: help!

I just put another lower into York Arms' build queue. I've got the image done for the mag well, with thanks to Larry Correia for the use of the inverted caduceus:

(It's in the glossary of "Hard Magic", if you're wondering. The text is from Revelations 6:8, and the layout is all me.)

What I'm lacking, unfortunately, is ideas for selector markings, and I'd appreciate suggestions. Vaguely biblical is fine (hm ... safe/fire/brimstone?), otherwise apropos is good. Ready? Go!