It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that Sayyiduna Anas (may Allah be pleased with him) passed by some children and greeted them with salam, and said that the Prophet (peace and blessings of Allah be upon him) would also greet children with salam.
Hadith Referenceالادب المفرد / كتاب السلام / 1043
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : صحيح البخاري ، الاستئذان ، حديث : 6247»
It is narrated from Anbasa bin Ammar, may Allah have mercy on him, that he said: I saw Sayyiduna Ibn Umar, may Allah be pleased with them both, greeting the children in the school with salam.