'A'isha (Allah be pleased with her) said that the Prophet (ﷺ) forbade to observe fast on two days-the day of Fitr and the day of Adha.
The Prohibition Explained
This noble hadith from Sahih Muslim 1140 establishes a clear prohibition from the Messenger of Allah (ﷺ) against fasting on two specific days: Eid al-Fitr (the Festival of Breaking Fast) and Eid al-Adha (the Festival of Sacrifice). These are days of celebration, feasting, and gratitude to Allah.
Scholarly Commentary from The Book of Fasting
The wisdom behind this prohibition, as explained by classical scholars, is that these days are designated by Allah as occasions for joy, eating, drinking, and remembering His blessings. Fasting on these days contradicts their very purpose and spirit.
Imam An-Nawawi, in his commentary on Sahih Muslim, states that the prohibition is a matter of consensus (ijma') among scholars and that fasting on these days is categorically forbidden (haram).
The Two Days of Eid
The day of Fitr (1st of Shawwal) marks the completion of the blessed month of Ramadan. The day of Adha (10th of Dhul-Hijjah) coincides with the Hajj pilgrimage and commemorates the sacrifice of Prophet Ibrahim (AS). Both are integral to Islamic tradition.
This ruling applies to voluntary (nafl) fasts as well as obligatory ones. It is a sin to intentionally fast on these days, and such a fast is invalid and not accepted by Allah.