Muwatta Malik 1756
موطأ مالك#1756Sahihحَدَّثَنِي عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " يُسَلِّمُ الرَّاكِبُ عَلَى الْمَاشِي وَإِذَا سَلَّمَ مِنَ الْقَوْمِ وَاحِدٌ أَجْزَأَ عَنْهُمْ " .
Yahya related to me from Malik from Zayd ibn Aslam that the Messenger of Allah, may Allah bless him and grant him peace, said, "The one riding greets the one walking, and when one of a group of people gives a greeting, it is enough for all of them
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:
Salim al-HilaliSahih Lighairihi
In-book reference: 53:1