It is possibly the earliest form of freemasonry, and it survives.
Arab history is full of instances of a warrior laying down his life for an enemy who has claimed protection from him.

And young de Crespigny was ruler of the most unruly city in the Near East because he understood better than most men how to respect Arab prejudices.

Ayisha accepted a cigarette, fitted it into a long amber tube, and watched him.
"Very well," he said at last.

"If I protect you you must answer questions.

Are you Ali Higg's wife ?" "Have I Your Honor's promise of protection ?" "Yes.