Full Sharh — Sahih Muslim 1760
وَحَدَّثَنَا أَبُو كُرَيْبٍ، وَهَارُونُ بْنُ عَبْدِ اللَّهِ، قَالاَ حَدَّثَنَا أَبُو أُسَامَةَ، عَنِ الْوَلِيدِ بْنِ كَثِيرٍ، قَالَ حَدَّثَنِي عُبَيْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ ابْنَ عُمَرَ، حَدَّثَهُمْ أَنَّ رَجُلاً نَادَى رَسُولَ اللَّهِ صلى الله عليه وسلم وَهُوَ فِي الْمَسْجِدِ فَقَالَ يَا رَسُولَ اللَّهِ كَيْفَ أُوتِرُ صَلاَةَ اللَّيْلِ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ صَلَّى فَلْيُصَلِّ مَثْنَى مَثْنَى فَإِنْ أَحَسَّ أَنْ يُصْبِحَ سَجَدَ سَجْدَةً فَأَوْتَرَتْ لَهُ مَا صَلَّى " . قَالَ أَبُو كُرَيْبٍ عُبَيْدُ اللَّهِ بْنُ عَبْدِ اللَّهِ . وَلَمْ يَقُلِ ابْنِ عُمَرَ .
English Translation
Ibn 'Umar reported:A person called (the attention) of the Messenger of Allah (ﷺ) as he was in the mosque, and said: Messenger of Allah, how should I make the rak'ahs of the night prayer an odd number? Upon this the Messenger of Allah (may peace he upon him) said: He who prays (night prayer) he should observe it in pairs, but if he apprehends the rise of morning, he should observe one rak'ah; that would make the number odd (for the rak'ahs) observed by him. This was narrated by Abu Kuraib 'Ubaidullah b. 'Abdullah and Ibn 'Umar did not make mention of it
Source
Sahih Muslim(صحيح مسلم)
The Book of Prayer - Travellers
Hadith Number
1760