Chapter 127 – Private Fast Days
127.1) Fast whenever a calamity hits you.
127.2) When you plan to fast, make a resolution to do so on the preceding day during the Shemoneh esreh (eighteen; silent prayer) of the Minhah.
127.3) You do not need to speak aloud your plan to fast during the 10 days of penitence, on the first day of Selihot, or the day before Rosh ) Hashanah.
127.4) Even if you do not orally vow to fast, if you think about it, you are obligated to do it.
127.5) When fasting, do not indulge in pleasure.
127.6) You may rinse your mouth with water.
127.7) Fast until the stars come out.
127.8) Do not boast about fasting.
127.9) Say certain prayers during and concluding a private fast. (See source for details, or consult a rabbi.)
127.10) If you do not specify the number of days you are going to fast and are invited to partake of a meal, you should eat.
127.11) If you have vowed to fast, you may no longer substitute the fast day.
127.12) If your fast causes great distress, you may redeem it with money given to the poor.
127.13) You may change the order of days of a vowed fast as long as the day is the same day of the week as vowed.
127.14) There are occasions when a person fasting may partake of a feast. See the source for details.
127.15) Once you terminate your fast by eating at a religious feast, you may eat thereafter.
127.16) If you illegally eat on a fast day, you must make amends the following week.
127.17) If you fast due to another’s distress and the distress is solved before the fasting period ends, you must fast as you vowed to.
12718) Fasting and repentance completely nullify the boding of an evil dream.