Luke documents that Paul initially worked as a tentmaker when staying in the city of Corinth. Making tents paid the bills so that every Sabbath, Paul could be found in the synagogue, trying to persuade Jews and Greeks that Jesus was the Messiah. We don’t have any further detail, but it sounds like he may have plied his secular trade as many as six days a week during this period.
That was before the invention of sewing machines. If his fingers got sore, it was not from flipping the pages of one too many Bibles.