Fasting in the month of Muharram

عَنْ أَبِی هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَٰهِ صَلَّی اللهُ عَلَيْهِ وَسَلَّمَ أَفْضَلُ الصِّيَامِ بَعْدَ صِيَامِ شَهْرِ رَمَضَانَ شَهْرُ اللَٰهِ الْمُحَرَّمُ ‏

Hazrat Abu Hurairah^ra narrates that the Holy Prophet^sa said, “The most virtuous fasting after the month of Ramadan is Allah’s month, Muharram.”

(Jami‘ al-Tirmidhi, Kitab al-Saum an rasool Allah, Hadith 740)