The Book of Prayer
Bulugh al-Maram #448
كتاب الصلاة
وَعَنْ أَبِي هُرَيْرَةَ - رضى الله عنه - قَالَ: قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -«أَفْضَلُ اَلصَّلَاةِ بَعْدَ اَلْفَرِيضَةِ صَلَاةُ اَللَّيْلِ» أَخْرَجَهُ مُسْلِمٌ.
Narrated Abu Hurairah (RA):
Allah's Messenger (ﷺ) said: “The most excellent prayer after that which is obligatory is the (voluntary) late night prayer.”
وَعَنْ أَبِي هُرَيْرَةَ - رضى الله عنه - قَالَ : قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -"أَفْضَلُ اَلصَّلَاةِ بَعْدَ اَلْفَرِيضَةِ صَلَاةُ اَللَّيْلِ" أَخْرَجَهُ مُسْلِمٌ .
Allah's Messenger (ﷺ) said: "The most excellent prayer after that which is obligatory is the (voluntary) late night prayer."
— Bulugh al-Maram, Hadith 448