The 365 · Sunnah · Day 216 · Fasting
Ayyām al-Bīḍ: The Three White Days of Each Month
The hadith
صِيَامُ ثَلَاثَةِ أَيَّامٍ مِنْ كُلِّ شَهْرٍ صِيَامُ الدَّهْرِ
The Prophet ﷺ said: 'Fasting three days of every month is like fasting the whole year' (Bukhārī 1979, Muslim 1159). And he ﷺ specified: 'O Abū Dharr, if you fast three days of the month, fast the 13th, 14th, and 15th' (Tirmidhī 761, Nasāʾi 2424). These three days are called ayyām al-bīḍ, the white days, because the moon is full on those nights and the nights are bright.
Svenska: Profeten ﷺ: 'Att fasta tre dagar varje månad är som att fasta hela året.' (Bukhārī 1979)
Bukhari 1979, Muslim 1159, Tirmidhi 761, Nasai 2424
The story
Abū Dharr al-Ghifārī, one of the closest Companions, asked the Prophet ﷺ about the most virtuous fasting practice for a believer who could not fast every other day (the practice of Dawud, the most beloved fasting to Allah). The Prophet ﷺ directed him: 'fast three days of each month; for every good deed is multiplied by ten, so that is like fasting the whole year.' Then he specified the 13th, 14th, and 15th. Abū Dharr, who became known for his asceticism, maintained this practice for the rest of his life. The Companions adopted it widely. Imam al-Nawawī commented: 'fasting three days from each month is preferred, and the most preferred are the white days.'
Why it's here
Because the Prophet ﷺ attached an extraordinary multiplier to a manageable practice. Three days a month, fasted across twelve months, equals 36 days. The Quranic rule that one good deed is multiplied tenfold (al-Anʿām 6:160) makes 36 days equal to 360, essentially a complete year of fasting. The Prophet ﷺ specifically named the 13th, 14th, and 15th of the lunar month as the optimal days. Why these three? They surround the full moon, and the Prophet ﷺ, in his sensitivity to the cosmic rhythm, anchored the believer's monthly fast to the lunar cycle. The white nights illumine the nights of these fasts; the believer rests in light after a day of worship.
Try it today
1) Add the next 13th, 14th, 15th of the current lunar month to your calendar; 2) Plan suhoor (a light pre-fajr meal); 3) Make the niyyah the night before each fast; 4) Break with dates and water at maghrib; 5) Use the fasting day for extra Quran, dhikr, and duʿā; 6) Track the practice monthly; missing one month is no shame, the return is the discipline.
In your day
Mark the 13th, 14th, 15th of each lunar month in your calendar. Set reminders. Use an Islamic-calendar app or the SalatTid calendar. Make the niyyah the night before. Begin with one day and build to all three. The fast covers the day-time; the celebration of having earned a year's-worth-of-fasting reward is internal. Pair the fast with extra Quran reading and duʿā to maximize the day.
A reflection to carry
The Prophet ﷺ told Abū Dharr: fast three days of each month, and it counts as fasting the whole year. The math is in the Quran's 10x multiplier (al-Anʿām 6:160). And he ﷺ specified the most virtuous three: the 13th, 14th, 15th of the lunar month. The white days, when the moon is full. Why these specifically? The Prophet ﷺ rooted the believer's monthly worship in the cosmic rhythm Allah set. The Muslim calendar is lunar; the believer's rhythm follows. Ya akhī, ya ukhtī, this is one of the highest-leverage practices in the dīn. Three days a month, 36 days a year of fasting, counted as 360 days of fasting on Allah's scale. The cost is manageable; the reward is extraordinary. Build the calendar reminder. Mark the next 13th. Plan suhoor. Build the niyyah. The Sunnah is at your fingertips.
Read the longer reflection
Yā Rabb, the Prophet ﷺ gave Abū Dharr the most elegant fasting-arithmetic. Three days of each month. A whole year of fasting in reward. And he specified the white days: 13th, 14th, 15th of the lunar month. The full moon nights. The cosmic anchor of the believer's monthly worship. Ya Allāh, forgive me for the years I have not built this practice. The lunar months that have passed without three days of fasting on the 13-14-15. The reward that would have stacked across my life had I begun this discipline at twenty. Begin me now. Place the next 13th of the lunar month in my calendar. Make me wake for suhoor. Make me close the fast with dates and water. Make me read extra Quran during the day. And if I miss a month, do not let me give up; bring me back the next month. Build the cumulative practice across my remaining years. And on the Day, when the fasts are presented, let me find that my three-white-days fasts, multiplied by Your tenfold rule, became the equivalent of decades of fasting in Your record. Āmīn ya Muqaddir.
Sources: Sahih Bukhari, Sahih Muslim, Abu Dawud, Tirmidhi, Nasai. The Qur'an and its translation are verified; the scholarship is retold faithfully in our own words and credited to its sources, never reproduced verbatim.
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