What was narrated concerning the (voluntary) night Prayer is two by two
حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ " صَلاَةُ اللَّيْلِ مَثْنَى مَثْنَى " .
It was narrated from Ibn ‘Umar that the Messenger of Allah (ﷺ) said: “The night prayer is (to be offered) two by two.”