Jimgrim and Allah's Peace by Talbot Mundy

"Do whatever the leader of the escort tells you."

I never learned exactly how Jim Grim got word to ben Nasir. My suspicion is that he took the simple course of getting the American Colony to send one of their men; but as they never referred to it afterwards, and might have their own reasons for keeping silence, I took care not to ask them. We have most of us seen harm done by noisy gratitude for kindness, better covered up.