Anas b. Malik reported that when Messenger of Allah ﷺ happened to pass by young boys he would great them.  

أَنَّ رَسُولَ اللَّهِ ﷺ مَرَّ عَلَى غِلْمَانٍ فَسَلَّمَ عَلَيْهِمْ  

This hadith has been narrated on the authority of Sayyar with the same chain of transmitters.  

أَخْبَرَنَا سَيَّارٌ بِهَذَا الإِسْنَادِ  

I was walking with Thibit al-Bunani that he happened to pass by children and he greeted them. And Thibit reported that he walked with Anas and he happened to pass by children and he greeted them. and Anas reported that he walked with Allah's Apostle (may peace be upon. him) and he happened, to pass by children and he greeted them.  

كُنْتُ أَمْشِي مَعَ ثَابِتٍ الْبُنَانِيِّ فَمَرَّ بِصِبْيَانٍ فَسَلَّمَ عَلَيْهِمْ وَحَدَّثَ ثَابِتٌ أَنَّهُ كَانَ يَمْشِي مَعَ أَنَسٍ فَمَرَّ بِصِبْيَانٍ فَسَلَّمَ عَلَيْهِمْ وَحَدَّثَ أَنَسٌ أَنَّهُ كَانَ يَمْشِي مَعَ رَسُولِ اللَّهِ ﷺ فَمَرَّ بِصِبْيَانٍ فَسَلَّمَ عَلَيْهِمْ