Thankfully, the Yom Kippur fast is behind us. One often wonders about fasting – and indeed even though we may not believe it after the drear of fasting – one of the world’s foremost cardiologists, Dr. Chauncey Crandall says fasting is actually beneficial to the body. This heart doctor says “the body cleanses itself – and surprisingly along with fasting, comes an increase in mental acuity. While extensive energy is needed to digest meals, when fasting, these energies can be used by the brain for better thinking. Amazingly, a well-nourished man can live from 50 to 75 days without food.”Some quotes and Jewish sources on fasting:

  • “The Second Temple period literature stressed that a fast without sincere repentance is valueless and senseless.”
  • “The Fast of Gedaliah, Tishri 3, commemorates the killing of the Jewish governor of Judah, a critical event in the downfall of the first commonwealth.”
  • “The Fast of Esther, Adar 13, commemorates the three days that Esther fasted before approaching King Ahasuerus on behalf of the Jewish people. The fast is connected with Purim. If Adar 13 falls on a Friday or Saturday, it is moved to the preceding Thursday, because it cannot be moved forward a day (it would fall on Purim).”
  • “The Fast of the Firstborn, Nissan 14, is a fast observed only by firstborn males, commemorating the fact that they were saved from the plague of the firstborn in Egypt. It is observed on the day preceding Passover.”
  • “The Fast of Tammuz, Tammuz 17, is the date when the walls of Jerusalem were breached, another major event leading up to the destruction of the First Temple.”
  • “In the Book of Esther (4:16), Esther agreed to see the King uninvited, and asked the Jewish people to fast for three days beforehand. Esther called for a fast, knowing that through soul- searching the Jews would forge a spiritual connection necessary to make her mission successful.”
  • “The Jews fasted and prayed on the 13th of Adar in preparation for their defense against Haman’s decree. The Torah prescribes that whenever a Jewish army goes to war, the soldiers should spend the previous day fasting. This ensures that when they go out to battle, the soldiers will be well-focused on the fact that success or failure is in the hands of God.” Rabbi Shraga Simmons
  • “Yom Kippur, the Day of Atonement, is the holy of holies of Jewish time. It is that rarest of phenomena, a Jewish festival without food. Instead it is a day of fasting and prayer, introspection and self-judgment when, collectively and repeatedly, we confess our sins and pray to be written into God’s Book of Life.” Rabbi Jonathan Sacks
  • “In the ancient Near East, prayer and fasting were advocated as a means to have one’s requests fulfilled by the gods (Ahikar, Armenian version, 2:49, from where, it appears, the idea was derived in Tobit, short version, 2:8; cf. also Test. Patr., Ben. 1:4).
  • “Ordinary fast days lasted for the duration of the daylight hours; the important fasts were a full 24 hours. Fasts were held either for one day or sometimes for a series of three or seven days; occasionally even daily for a continued period.” Ta’an. 1:5–6; cf. also e.g., Judith 4:13
  • “The halakhah is that in such cases the individual, in contrast to the community, has to commit himself to fast during the afternoon of the preceding day (ibid.). It was also possible to fast for a specific number of hours.” Ta’an. 11b–12a