My boss and I are Muslims, one day some brave Jewish man walked into our shop and asked if we can do business together. I say brave as he is a conservative religion-wise you can tell from the way he dresses and his hair ie rabbi-like in spite of the fact that our area is strictly Arabs Muslims populated.
Since then we do business every week, he comes to deliver the goods himself.
What is a word that I can use to address him without offending him? something like "brother". Keep in mind that as a Muslim I am not allowed to use this word with non-Muslims.
My boss calls him rabbi and he calls my boss Imam. However one day he said he does not like being called rabbi.