A rabbi boarded a train one day and as he was sitting there, 3 teenagers decided to have some fun with him, so each one passed by him and the 1st one said: Good evening Father Abraham, the 2nd: Good evening Father Isaac, and the 3rd: Good evening Father Jacob. The rabbi quickly responded, I am none of them, rather I am Shaul ben Kish who went out to look for his 3 donkeys, it seems I have found them!
BS”D
A true version of this goes as follows:
A well known rav and askan with many connections in government and business circles was traveling by train. He was approached by a highly assimilated maskil who asked his name, and when finding out who he was addressing, he was shocked.
So, he said: “I did not know Rav () was so old-fashioned. I was expecting a modern type…”
The rav replied: “On the contrary, it is YOU who are old fashioned. Does it not say ‘mitchila oivdei avoido zoro hoyu avoisenu….'”
(I wish I could remember who this maaseh involved – it took place before WWI, I believe in “Lita”).