Inspired by the Japanese folklore, kitsune no yomeiri ("the fox's wedding"), which typically refers to the phenomenon of sunshowers or atmospheric ghost light. Seeing the event is usually considered a good omen, but could also mean danger, since the fickle kitsune could inflict harm to those they consider "uninvited guests".
It also brings to mind Matthew 5:45 - "For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust."
