'Uqba ibn 'Abdullah ibn 'Amr who said, "While we were sitting with the Prophet, may Allah bless him and grant him peace, in the shade of a tree while travelling between Makka and Madina, a bedouin, who was an example of the coarsest and fiercest kind of people came up and said, 'Peace be upon you,' and they said, 'And upon you.'"
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا يَحْيَى بْنُ سُلَيْمَانَ قَالَ: حَدَّثَنِي ابْنُ وَهْبٍ قَالَ: أَخْبَرَنِي حَيْوَةُ، عَنْ عُقْبَةَ بْنِ مُسْلِمٍ، عَنْ عَبْدِ اللهِ بْنِ عَمْرٍو قَالَ: بَيْنَمَا نَحْنُ جُلُوسٌ عِنْدَ النَّبِيِّ صلى الله عليه وسلم فِي ظِلِّ شَجَرَةٍ بَيْنَ مَكَّةَ وَالْمَدِينَةِ، إِذْ جَاءَ أَعْرَابِيٌّ مِنَ أَجْلَفِ النَّاسِ وَأَشَدِّهِمْ فَقَالَ: السَّلامُ عَلَيْكُمْ، فَقَالُوا: وَعَلَيْكُمُ.
sunnah.com