It is said that originally named Wu Pen, the Paosheng god was a native of Paichiao in Fukien province in the Sung dynasty, and an expert on astronomy, geography, medicine, manners, music, and administration. As he always helped to solve human problems during his lifetime, people believed he has been immortalized and have set up the Tzu Chi temple to honor him.
保生大帝本名叫做吳本，是宋朝時福建省同安縣白礁鄉人，他精通天文、地理、醫術、禮樂與行政，常為鄉人解決疑難、紛爭，為大家所愛戴與敬重。他死後，白礁鄉人相信他已成神，在鄉內建慈濟宮祭祀追懷他，並希望他繼續保護世人。