Sunan Ibn Majah, Hadith 106 ⓘ
It was narrated that 'Abdullah bin Salimah said: "I heard 'Ali say: 'The best of people after the Messenger of Allah is Abu Bakr, and the best of people after Abu Bakr is 'Umar.'"
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا شُعْبَةُ، عَنْ عَمْرِو بْنِ مُرَّةَ، عَنْ عَبْدِ اللَّهِ بْنِ سَلَمَةَ، قَالَ سَمِعْتُ عَلِيًّا، يَقُولُ خَيْرُ النَّاسِ بَعْدَ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ أَبُو بَكْرٍ وَخَيْرُ النَّاسِ بَعْدَ أَبِي بَكْرٍ عُمَرُ .
also referenced under: Book 1, Hadith 111 (In-Book) & Volume 1, Book 1, Hadith 106 (DarusSalam)