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
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Salim al-HilaliSahih Lighairihi
In-book reference: 53:1