[Avodah] Seudah shlishit on aharon shel Pesah

[David Riceman]

RAZ, in his recent article in Jewish Action, writes "there is a custom 
to have a third meal on the last day of Pesah".  I had hoped he would 
cite sources; the followers of both the Gaon and the Baal Shem Tov have 
this custom, but they cite very different reasons for it.  Were they 
both relying on a single earlier source, or did they develop the custom 
independently?

David Riceman