كتاب الصلاة
2  
The Book of Prayer
Bulugh al-Maram 369
Narrated Abu Hurairah (RA):
Allah's Messenger (ﷺ) said: "The most excellent prayer after that which is obligatory is the (voluntary) late night prayer." [Reported by Muslim].
وَعَنْ أَبِي هُرَيْرَةَ ‏- رضى الله عنه ‏- قَالَ : قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ أَفْضَلُ اَلصَّلَاةِ بَعْدَ اَلْفَرِيضَةِ صَلَاةُ اَللَّيْلِ } أَخْرَجَهُ مُسْلِمٌ .‏ 1
Reference : Bulugh al-Maram 369
In-book reference : Book 2, Hadith 369
English translation : Book 2, Hadith 364
Hadith Text
Reference