Rabbi Avraham Pam's father was a rabbi in Europe. Each Friday night, the shamash (attendant) would walk around the shul to greet all the guests in town, and to make sure that each one had a place to eat the Shabbos meal. As we would expect, distinguished-looking guests had no difficulty being invited; the congregants vied for the rights of hosting a guest bedecked in a perfectly pressed suit or frock. The bedraggled beggars who made their way from town to town, on the other hand, were usually not as fortunate; no one rushed to invite them for a meal. The shamash was charged with the unenviable task of distributing such guests among the reluctant worshipers who had not been lucky enough to host a "respectable" guest. If there was one person left over at the end of the shamash's rounds, you could be sure that the person was a true pauper, an uncouth, unsightly fellow whom no one would want at his Shabbos table.
Once, when the shamash finished his rounds, there were two people who had not been placed. One had the obvious mark of a Torah scholar; his dignified bearing bespoke refined character and scholarship. The other was a rather disheveled, corpulent fellow, the type of guest everyone avoided.
When the shamash asked Rabbi Pam's father whom he wanted to host, he asked for the obese man, and sent the Torah scholar with someone else. "If I were looking for a study partner," Rabbi Pam senior explained to the shamash, "I would have opted for that fine-looking gentleman. He looks like he knows how to learn very well. I am looking for a guest. To fulfill the mitzvah of hosting guests properly, you need someone who can eat. The fellow I chose looks like a good eater."