‘Assuredly,’ said Kurruk Shah with a grim chuckle. ‘Otherwise, why did I, who have served the Queen for seven-and-twenty years, and killed many hill-dogs, shout aloud for quarter when the lightning revealed us to the watch-towers? When I was a young man I saw the killing in the valley of Sheor-Kot there at our feet, and I know the tale that grew up therefrom. But how can the ghosts of unbelievers, prevail against us who are of the Faith?
This is from "Lost Legion" by Rudyard Kipling.
I don't understand the meaning of
shout aloud for quarter
I am glad if someone would kindly teach me.