Hadith on Fasting: The best fast after Ramadan is in the month of Muharram

Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, was asked about which prayer was most excellent after the prescribed prayer, and which fast was most excellent after the month of Ramadan. The Prophet said, “The best prayer after the prescribed prayers is prayer offered in the middle of the night, and the most excellent fast after the month of Ramadan is the fast in Allah’s month, Al-Muharram.

Source: Sahih Muslim 1163

Grade: Sahih (authentic) according to Muslim

عَنْ أَبِي هُرَيْرَةَ، رضى الله عنه يَرْفَعُهُ قَالَ سُئِلَ أَىُّ الصَّلاَةِ أَفْضَلُ بَعْدَ الْمَكْتُوبَةِ وَأَىُّ الصِّيَامِ أَفْضَلُ بَعْدَ شَهْرِ رَمَضَانَ فَقَالَ أَفْضَلُ الصَّلاَةِ بَعْدَ الصَّلاَةِ الْمَكْتُوبَةِ الصَّلاَةُ فِي جَوْفِ اللَّيْلِ وَأَفْضَلُ الصِّيَامِ بَعْدَ شَهْرِ رَمَضَانَ صِيَامُ شَهْرِ اللَّهِ الْمُحَرَّمِ

صحيح مسلم كتاب الصيام أفضل الصيام بعد رمضان شهر الله المحرم 1163