Hello all.

I cannot remember the name of a movie I saw many years ago.

I am a bit spotty about the details but it is about a man (who is dressed in all black Bedouin flowing garb and has a full dark beard) saving an elderly man in the desert.  They go through tough times together, including almost dying of thirst.

But eventually they end up back in civilization and it turns out that the man in black was actually out to kill the other older man.  But because he did not know the name of the older man and a face that goes with it, he did not put 2 and 2 together in the desert.

But then at the moment of him carrying out his assassination of the old man, he realizes that it is the same man that he had saved in the desert.

Any ideas…??

Thanks in advance.