Anas (May Allah be pleased with him) reported that he passed by some children and greeted them. Then he said:
"Messenger of Allah (ﷺ) used to do the same."[Al-Bukhari and Muslim]. (JA)
App reference (JA): Book 6, Hadith 18 (JA)
Arabic/English book reference (JA): Book 6, Hadith 862 (JA)