Hadith 3900
عَنِ النَّعْمَانِ بْنِ سَعْدٍ قَالَ: قَالَ رَجُلٌ لِعَلِيٍّ رَضِيَ اللَّهُ عَنْهُ: يَا أَمِيرَ الْمُؤْمِنِينَ! أَيُّ شَهْرٍ تَأْمُرُنِي أَنْ أَصُومَ بَعْدَ رَمَضَانَ؟ فَقَالَ: مَا سَمِعْتُ أَحَدًا سَأَلَ عَنْ هَذَا بَعْدَ رَجُلٍ سَأَلَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ فَقَالَ: يَا رَسُولَ اللَّهِ! أَيُّ شَهْرٍ تَأْمُرُنِي أَنْ أَصُومَ بَعْدَ رَمَضَانَ؟ فَقَالَ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ: ((إِنْ كُنْتَ صَائِمًا شَهْرًا بَعْدَ رَمَضَانَ فَصُمِ الْمُحَرَّمَ فَإِنَّهُ شَهْرُ اللَّهِ، وَفِيهِ يَوْمٌ تَابَ عَلَى قَوْمٍ، وَيَتُوبُ فِيهِ عَلَى قَوْمٍ))
Nu’man bin Sa’d reports that a man asked Sayyiduna Ali (may Allah be pleased with him): O Commander of the Faithful! Which month’s fasting do you command me to observe after Ramadan? He replied: I have not heard anyone ask this question except one man, who asked the Messenger of Allah (peace and blessings be upon him) the same question: O Messenger of Allah! After the month of Ramadan, which month’s fasting do you command me to observe? The Prophet (peace and blessings be upon him) said: If you wish to fast after Ramadan, then fast in the month of Muharram, for it is the month of Allah. In this month, Allah accepted the repentance of a people, and He will accept the repentance of another people.
Hadith 3901
عَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: سُئِلَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَيُّ الصَّلَاةِ أَفْضَلُ بَعْدَ الْمَكْتُوبَةِ؟ قَالَ: ((الصَّلَاةُ فِي جَوْفِ اللَّيْلِ))، قِيلَ: أَيُّ الصِّيَامِ أَفْضَلُ بَعْدَ رَمَضَانَ؟ قَالَ: ((شَهْرُ اللَّهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ))
It is narrated from Sayyiduna Abu Huraira, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, was asked: "Which prayer is the best after the obligatory prayers?" He, peace and blessings be upon him, replied: "Prayer at any time during the night." Then someone asked: "Which fasts are the best after those of Ramadan?" He, peace and blessings be upon him, replied: "The fasts of Allah’s month, which you call Muharram."