The Fast of the Firstborn is the only fast in the Jewish calendar which is neither an atonement for sin nor a fast of petition. Observed only symbolically by firstborn male Jews on the day before Passover, its main purpose appears to be to remind Jews of the Angel of Death’s slaying of the Egyptians’ firstborn sons and the miraculous escape of their own sons. The obligation to fast can be avoided by participating in a siyyum—the study of a particular passage of the Talmud. Discuss
Source: The Free Dictionary