On the Fast of the Firstborn

Fast of the Firstborn (Heb. תַּעֲנִית בְּכוֹרִים, ta'anit bekhorim), fast observed by primogenital males on the 14th of Nisan i.e., the day before *Passover. This traditional custom seems to stem from the desire to express gratitude for the saving of the firstborn Israelites during the tenth plague in Egypt (Ex. 13:1ff.). According to talmudic sources (Soferim, ed. by M. Higger (1937), 21:1) the custom was already observed in mishnaic times. Another source mentions that R. Judah ha-Nasi fasted on this day; his fasting, however, is explained by some as a wish to stimulate his appetite for the maẓẓah (unleavened bread) at the seder meal (TJ, Pes. 10:1,37b and compare Soferim, loc. cit.). The fast became an accepted traditional custom obliging all males whether firstborn to their father or only to their mother, and in some opinions even firstborn women, to fast (Sh. Ar., OḤ 470:1). If a child is too young to fast (under the age of 13), his father fasts instead of him; if the father is firstborn, the child's mother fasts in lieu of the child (Isserles to OḤ 470:2). Should the first day of Passover be on a Sabbath, the fast is observed on the preceding Thursday; according to amore lenient ruling, it is suspended (ibid.). However, since one is permitted to break this fast in order to partake of a se'udat mitzvah (a meal accompanying a religious celebration, such as a circumcision) it was laid down that the celebration of the hadran constituted such a meal. The custom thus evolved to finish the study of a Talmud tractate on the morning before Passover, at which occasion a festive banquet is arranged in the synagogue, at which firstborns participate, and they need not therefore fast. Through this device, the Fast of the Firstborn is practically in desuetude (see *Fasting and Fast days).