مِشْكَاةُ الْمَصَابِيحِ
Mishkat al-Masabih 1236
Prayer
Encouragement to get up during the Night - Section 3
وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «أَفْضَلُ الصَّلَاةِ بَعْدَ الْمَفْرُوضَةِ صَلَاةٌ فِي جَوف اللَّيْل» . رَوَاهُ أَحْمد
Abu Huraira said he heard God’s Messenger say, “The most excellent prayer after that which is obligatory is one in the depth of the night.” Ahmad transmitted it.
Mishkat al-Masabih, 1236صَحِيحٌ (الألباني)