Sayyar reported: I was walking with Thibit al-Bunani that he happened to pass by children and he greeted them. And Thabit 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 (ﷺ) and he happened to pass by children and he greeted them.
´Narrated Sayyar:` "I was walking with Thabit Al-Bunani. He passed by some boys, so he said Salam to them. Then Thabit said: 'I was with Anas when he passed by some boys and gave the Salam to them, and Anas said: I was with the Prophet (ﷺ) when he passed by some boys and he gave the Salam to them.'"
Shaykh Dr. Abdur Rahman Freywai
Explanation: 1: There are several benefits in greeting children with salam:
➊ It expresses humility in the one who gives the salam.
➋ Children become acquainted with Islamic manners.
➌ Salam also brings comfort and encouragement to them.
➍ The importance of salam becomes clear to them.
➎ They become aware that this is a Sunnah of the Messenger (sallallahu alayhi wa sallam), and acting upon it is very important.
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 2696