The Prophet ﷺ came upon some children who were playing and greeted them with peace.
حدثنا حجاج عن سليمان بن المغيرة عن ثابت البناني
أن النبي ﷺ أتى على صبيان وهم يلعبون فسلم عليهم
Its isnad is sahih. It has been mentioned previously, and it is found in Bukhari 11/32, no. 6247, Fath al-Bari, in the Book of Seeking Permission, chapter on greeting children with salaam, and in Muslim 4/1708, no. 2168, in the Book of Greetings, with similar wording.