عَنِ ابْنِ عُمَرَ أَيْضًا أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ: ((صَلَاةُ الْمَغْرِبِ وَتْرُ صَلَاةِ النَّهَارِ، فَأَوْتِرُوا صَلَاةَ اللَّيْلِ، وَصَلَاةُ اللَّيْلِ مَثْنَى مَثْنَى، وَالْوِتْرُ رَكْعَةٌ مِنْ آخِرِ اللَّيْلِ))
It is also narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: The Maghrib prayer is the witr of the day’s prayers, and you should make the night prayers odd (by performing witr), and the night prayer is in sets of two rak‘ahs, and at the end of the night, witr is one rak‘ah.