Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
tirmidhi:2703Muḥammad b. al-Muthanná And ʾIbrāhīm b. Yaʿqūb > Rawḥ b. ʿUbādah > Ḥabīb b. al-Shahīd > al-Ḥasan > Abū Hurayrah

from Abu Hurairah that the Prophet ﷺ said: "The rider gives the Salam to the walking person, and the walking person to the sitting person and the few to the many." Ibn Al-Muthanna added in his narration: "And the young one gives the Salam to the elder."  

الترمذي:٢٧٠٣حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى وَإِبْرَاهِيمُ بْنُ يَعْقُوبَ قَالاَ حَدَّثَنَا رَوْحُ بْنُ عُبَادَةَ عَنْ حَبِيبِ بْنِ الشَّهِيدِ عَنِ الْحَسَنِ عَنْ أَبِي هُرَيْرَةَ

عَنِ النَّبِيِّ ﷺ قَالَ يُسَلِّمُ الرَّاكِبُ عَلَى الْمَاشِي وَالْمَاشِي عَلَى الْقَاعِدِ وَالْقَلِيلُ عَلَى الْكَثِيرِ وَزَادَ ابْنُ الْمُثَنَّى فِي حَدِيثِهِ وَيُسَلِّمُ الصَّغِيرُ عَلَى الْكَبِيرِ وَفِي الْبَابِ عَنْ عَبْدِ الرَّحْمَنِ بْنِ شِبْلٍ وَفَضَالَةَ بْنِ عُبَيْدٍ وَجَابِرٍ  

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ قَدْ رُوِيَ مِنْ غَيْرِ وَجْهٍ عَنْ أَبِي هُرَيْرَةَ وَقَالَ أَيُّوبُ السَّخْتِيَانِيُّ وَيُونُسُ بْنُ عُبَيْدٍ وَعَلِيُّ بْنُ زَيْدٍ إِنَّ الْحَسَنَ لَمْ يَسْمَعْ مِنْ أَبِي هُرَيْرَةَ

See similar narrations below:

Collected by Dārimī
darimi:2676ʿAbdullāh b. Yazīd > Ḥaywah > Abū Hāniʾ al-Khawlānī > Abū ʿAlī al-Janbī > Faḍālah b. ʿUbayd

that the Messenger of Allah ﷺ said: "The horseman gives Salam to the walking person, the walking person to the one standing and the few to the many." (Using translation from Tirmidhī 2705)   

الدارمي:٢٦٧٦أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ يَزِيدَ حَدَّثَنَا حَيْوَةُ أَخْبَرَنَا أَبُو هَانِئٍ الْخَوْلَانِيُّ

أَنَّ أَبَا عَلِيٍّ الْجَنْبِيَّ حَدَّثَهُ عَنْ فَضَالَةَ بْنِ عُبَيْدٍ عَنْ رَسُولِ اللَّهِ ﷺ قَالَ «يُسَلِّمُ الرَّاكِبُ عَلَى الْمَاشِي وَالْقَائِمُ عَلَى الْقَاعِدِ وَالْقَلِيلُ عَلَى الْكَثِيرِ»