Q. Some people fast three days of every Month. Is there any virtue for it?
A. It is Mustahab (preferable) to fast three days of every lunar Month. It is also Mustahab (preferable) to keep the three days fast on the 13th, 14th and 15th of every lunar Month respectively. (Maraaqil-Falaah 2/297-298)
The 13th, 14th and 15th fasts of every lunar Month is known as Al-Ayyaamul Beedh (the fast of the white days). It was given this name due to the moon being at is fullest and brightest on these days.
Rasoolullah Sallallahu Alaihi Wasallam said to Abu Zarr Radhiallahu Anhu: “O Abu Zarr! When you fast three days out of a month, then fast the thirteenth, fourteenth, and fifteenth.”(Tirmidhi)
May Allah Ta’ala grant one and all the ability to revive this noble act. Ameen.
Allah Ta’ala Knows Best
Mufti Ismaeel Bassa