Prayer offered in the middle of the night and the most excellent fast after (fasting) in the month of Ramadan is the fast in God's month al-Muharram.  

عَنْ أَبِي هُرَيْرَةَ ؓ 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  

"The Messenger of Allah ﷺ said: 'The best fasting after the month of Ramadan is the month of Allah, Al-Muharram, and the best prayer is prayer at night.'"  

قَالَ رَسُولُ اللَّهِ ﷺ أَفْضَلُ الصِّيَامِ بَعْدَ شَهْرِ رَمَضَانَ شَهْرُ اللَّهِ الْمُحَرَّمُ وَأَفْضَلُ الصَّلاَةِ بَعْدَ الْفَرِيضَةِ صَلاَةُ اللَّيْلِ  

The Messenger of Allah ﷺ as saying: The most excellent fast after Ramadan is Allah's month al-Muharram, and the most excellent prayer after the prescribed prayer is the prayer during night.  

قَالَ رَسُولُ اللَّهِ ﷺ أَفْضَلُ الصِّيَامِ بَعْدَ شَهْرِ رَمَضَانَ شَهْرُ اللَّهِ الْمُحَرَّمُ وَإِنَّ أَفْضَلَ الصَّلاَةِ بَعْدَ الْمَفْرُوضَةِ صَلاَةٌ مِنَ اللَّيْلِ لَمْ يَقُلْ قُتَيْبَةُ شَهْرِ قَالَ رَمَضَانَ  

“A man came to the Prophet ﷺ and said: ‘Which fasting is better after the month of Ramadan?’ He said: ‘The month of Allah which is called Muharram.’”  

جَاءَ رَجُلٌ إِلَى النَّبِيِّ ﷺ فَقَالَ أَىُّ الصِّيَامِ أَفْضَلُ بَعْدَ شَهْرِ رَمَضَانَ قَالَ شَهْرُ اللَّهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ  

[Machine] The Messenger of Allah ﷺ was asked, "Which prayer is the best after the obligatory ones?" He replied, "The prayer in the middle of the night." Then he was asked, "Which fasting is the best after Ramadan?" He said, "The month of Allah which you call Muharram."  

سُئِلَ رَسُولُ اللهِ ﷺ أَيُّ الصَّلَاةِ أَفْضَلُ بَعْدَ الْمَكْتُوبَةِ؟ قَالَ الصَّلَاةُ فِي جَوْفِ اللَّيْلِ قِيلَ أَيُّ الصِّيَامِ أَفْضَلُ بَعْدَ رَمَضَانَ؟ قَالَ شَهْرُ اللهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ  

"The Messenger of Allah ﷺ said: 'The best fasting after the month of Ramadan is the month of Allah, Al-Muharram, and the best prayer is prayer at night.'" (Using translation from Nasāʾī 1613)   

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ أَفْضَلُ الصَّلَاةِ بَعْدَ الْمَفْرُوضَةِ صَلَاةٌ فِي جَوْفِ اللَّيْلِ وَأَفْضَلُ الصِّيَامِ بَعْدَ شَهْرِ رَمَضَانَ شَهْرُ اللهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ  

"The Messenger of Allah ﷺ said: 'The best fasting after the month of Ramadan is the month of Allah, Al-Muharram, and the best prayer is prayer at night.'" (Using translation from Nasāʾī 1613)   

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ أَفْضَلُ الصَّلَاةِ بَعْدَ الْمَفْرُوضَةِ صَلَاةُ اللَّيْلِ وَأَفْضَلُ الصِّيَامِ بَعْدَ رَمَضَانَ شَهْرُ اللهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ  

"The Messenger of Allah ﷺ said: 'The best fasting after the month of Ramadan is the month of Allah, Al-Muharram, and the best prayer is prayer at night.'" (Using translation from Nasāʾī 1613)  

قَالَ رَسُولُ اللَّهِ ﷺ «أَفْضَلُ الصِّيَامِ بَعْدَ شَهْرِ رَمَضَانَ شَهْرُ اللَّهِ الْمُحَرَّمُ وَأَفْضَلُ الصَّلَاةِ بَعْدَ الْفَرِيضَةِ صَلَاةُ اللَّيْلِ»  

"The Messenger of Allah ﷺ said: 'The best fasting after the month of Ramadan is the month of Allah, Al-Muharram, and the best prayer is prayer at night.'" (Using translation from Nasāʾī 1613)   

كَانَ رَسُولُ اللهِ ﷺ يَقُولُ «إِنَّ أَفْضَلَ الصَّلَاةِ بَعْدَ الْمَفْرُوضَةِ الصَّلَاةُ فِي جَوْفِ اللَّيْلِ وَأَفْضَلَ الصِّيَامِ بَعْدَ رَمَضَانَ شَهْرُ اللهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ»  

[Machine] The Messenger of Allah ﷺ was asked: "Which prayer is best after the obligatory prayers?" He replied, "The prayer in the middle of the night." He was asked: "Which fasting is best after Ramadan?" He replied, "The month of Allah, which you call Muharram."  

سُئِلَ رَسُولُ اللهِ ﷺ أَيُّ الصَّلَاةِ أَفْضَلُ بَعْدَ الْمَكْتُوبَةِ؟ قَالَ «الصَّلَاةُ فِي جَوْفِ اللَّيْلِ» قِيلَ أَيُّ الصِّيَامِ أَفْضَلُ بَعْدَ رَمَضَانَ؟ قَالَ «شَهْرُ اللهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ»  

"The Messenger of Allah ﷺ said: 'The best fasting after the month of Ramadan is the month of Allah, Al-Muharram, and the best prayer is prayer at night.'" (Using translation from Nasāʾī 1613)   

كَانَ النَّبِيُّ ﷺ يَقُولُ إِنَّ أَفْضَلَ الصَّلَاةِ بَعْدَ الْمَفْرُوضَةِ الصَّلَاةُ فِي جَوْفِ اللَّيْلِ وَإِنَّ أَفْضَلَ الصِّيَامِ بَعْدَ شَهْرِ رَمَضَانَ شَهْرُ اللهِ الَّذِي تَدْعُونَهُ الْمُحَرَّمَ  

The most excellent fast after Ramadan is God's month. al-Muharram, and the most excellent prayer after what is prescribed is prayer during the night. (Using translation from Muslim 1163a)   

"أفْضَلُ الصلاة بعدَ المكتوبةِ: الصلاةُ في جوفِ الليل، وأفْضَلُ الصيام بعد شهرِ رمضان: شَهْرُ الله المُحَرَّمُ" .  

"إِنَّ أَفضَل الصلاةِ بعد الفريضة الصلاةُ في جوف الَّليلِ، وإِنَّ أَفضَل الصِّيامِ بعد شَهرِ رمضانَ الشَّهرُ الذى تدعُونه الْمُحَرَّم".