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 wasnarrated from Ibn ‘Umar that the Messenger of Allah (PBUH)said: “The night prayer is (to be offered) two by two.” Translation Not Available

Book Ref: Sunan Ibn Majah Book 5 Hadith 1319
Web Ref:  Sunan Ibn Majah Vol 1 Book 5 Hadith 1319