Iggeres HaT’Shuva: Beggining of Chapter Three; Tammuz 10, 5775
Previously, the Alter Rebbe established what fasting is for. Now he explains that there is a set number of fasts for every sin. If we did a sin that requires 84 fasts, but we did the sin ten or twenty times, we still only fast 84 x 3. Not because we’re lenient, but because after three times, the damage has spread to the furthest reaches.