If you fast the 10th of Muharram, do you have to fast the 9th too?

Yes, if you plan to fast the 10th of Muharram (Ashura) then you should fast the 9th or 11th too. If one fasts the 10th alone then it is Makruh.

عَبْدَ اللهِ بْنَ عَبَّاسٍ رَضِيَ اللهُ عَنْهُمَا، يَقُولُ: حِينَ صَامَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ يَوْمَ عَاشُورَاءَ وَأَمَرَ بِصِيَامِهِ قَالُوا: يَا رَسُولَ اللهِ إِنَّهُ يَوْمٌ تُعَظِّمُهُ الْيَهُودُ وَالنَّصَارَى فَقَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ: فَإِذَا كَانَ الْعَامُ الْمُقْبِلُ إِنْ شَاءَ اللهُ صُمْنَا الْيَوْمَ التَّاسِعَ

(Sayidina) Abdullah bin Abbas (May Allah Most High be pleased with them both) said, when the Messenger of Allah ﷺ fasted on the day of ‘Ashura and commanded others to fast it, they (his Companions) said to him ﷺ, ‘ O Messenger of Allah (ﷺ), it is a day which the Jews and Christians venerate. Thereupon the Messenger of Allah ﷺ said, ‘When the next year comes, In sha Allah, we will fast on the ninth (too).’ (Sahih Muslim, 1134 – 133).

In the Hadith above we find the Holy Prophet ﷺ wanting to differentiate this Ummah from other religious communities. This concern of the Prophet ﷺ is mentioned in numerous Hadith. He ﷺ always wanted us to be unique and stand apart from other religions and their practices.

Based on the Hadith above a person wanting to fast on the tenth of Muharram (Ashura) should fast the ninth too. Fasting the tenth and eleventh is also permitted, since the purpose is to avoid isolating the tenth. There is an explicit Hadith mentioning the day before and after:

ابْنِ عَبَّاسٍ، قَالَ: قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ:  صُومُوا يَوْمَ عَاشُورَاءَ، وَخَالِفُوا فِيهِ الْيَهُودَ، صُومُوا قَبْلَهُ يَوْمًا، أَوْ بَعْدَهُ يَوْمًا 

(Sayidina Abdullah) Ibn Abbas (May Allah Most High be pleased with them both) narrated that the Messenger of Allah ﷺ said, ‘Fast the day of Ashura. Be different to the Jews, fast the day before it or after it.’ (Ahmad 241, weak).

Although the above Hadith is weak. The basic principle is established through authentic Hadith. Which is to differentiate our fasting from that of the Jews and thus fast an extra day. For this reason Hanafi scholars mentioned both options. One can either fast the 9th and the 10th or the 10th and the 11th.

المسنون فهو صوم عاشوراء فإنه يكفر السنة الماضية مع صوم التاسع

قوله: مع صوم التاسع: أي أو الحادي عشر لما يأتي للمصنف فتنتفي الكراهة بضم يوم قبله أو بعده. (حاشية الطحطاوي على مراقي الفلاح)

Imam al-Shurunbulali: And the Sunnah fast is the day of Ashura, for it expiates for the sins of the previous year, together with the ninth.

Imam al-Tahtawi: His saying, ‘together with the ninth,’ meaning or the eleventh due to what the author will mention later, that it is no longer Makruh if a person adds a day before it (the tenth) or after it. (Haashiyah Tahtawi ala Maraaqi al-Falah).

And Allah Most High Knows Best.

-Answered by Shaykh Noorud-deen Rashid (03.08.2022)

See also:
Fasting the Day of Ashura

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