Sunan Abi Dawud 1438
سنن أبي داود#1438Sahihحَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا يَحْيَى، عَنْ عُبَيْدِ اللَّهِ، حَدَّثَنِي نَافِعٌ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " اجْعَلُوا آخِرَ صَلاَتِكُمْ بِاللَّيْلِ وِتْرًا " .
Ibn 'Umar reported the Prophet (ﷺ) as suing:Make the last of your prayer at night a witr
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (998) Sahih Muslim (751)
In-book reference: 8:23