Duck, Duck, Haddock!

A favorite story often told by Marash Girl's dad, who had close friends in both the Jewish and Roman Catholic communities, was the following.

Although he was Jewish, Isaac lived in a Roman Catholic community, and decided that, in order to be a part of the community, he should join the Roman Catholic Church.  He went to the church, and related his decision to the priest.  The priest, after going through the conversion ritual, held his hand over Isaac, intoning, Isaac, Isaac, you are now McIsaac.

Several years later, McIsaac invited the priest home for dinner.  McIsaac welcomed the priest into his dining room, and after the priest said grace,  McIsaac, with great fanfare, brought in the Friday night dinner on a platter.
The priest was startled to see that there was duck on the platter.
McIsaac, don't you know that we Catholics cannot eat meat on Friday?
McIsaac paused and answered,  "Isaac, Isaac, McIsaac; Duck, Duck, Haddock."