Abdullah bin Umar reported,

He told them that a man called out to the Messenger of Allah ﷺ while he was in the mosque, saying, "Messenger of Allah, how should I make my night prayer odd-numbered?"The Messenger of Allah ﷺ replied, "Whoever prays should pray in pairs of two. Then, if he senses that morning is approaching, let him perform a single prostration, which will make all that he has prayed odd-numbered."Abu Kurayb said, "Ubaydullah bin Abdullah," and did not say, "Ibn Umar."

Muslim 1760

Sahih

و حدثنا أبو كريب وهارون بن عبد الله قالا حدثنا أبو أسامة عن الوليد بن كثير قال حدثني عبيد الله بن عبد الله بن عمر أن

ابن عمر

حدثهم أن رجلا نادى رسول الله ﷺ وهو في المسجد فقال يا رسول الله كيف أوتر صلاة الليل فقال رسول الله ﷺ من صلى فليصل مثنى مثنى فإن أحس أن يصبح سجد سجدة فأوترت له ما صلى قال أبو كريب عبيد الله بن عبد الله ولم يقل ابن عمر

مسلم 1760صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Travelers' prayer and its shortening
Chapter
Night prayer is two rakats at a time and Witr is one rakat at the end of the night
Numbering
Darussalam 1760
Muslim 1760