(20) باب صَلاَةُ اللَّيْلِ مَثْنَى مَثْنَى وَالْوِتْرُ رَكْعَةٌ مِنْ آخِرِ اللَّيْلِ
Salim reported on the authority of his father that a person asked the Messenger of Allah (ﷺ) about the night prayer. He said:
It consists of pairs of rak'ahs, but if one fears morning is near, he should make it an odd number by praying one rak'ah. (PT)
Reference (PT): Sahih Muslim 749 b (PT)
In-book reference (PT): Book 6, Hadith 178 (PT)
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1633 (PT)