Sahih Muslim
The Book on Salutations and Greetings (Kitab As-Salam)
Book Number: 026 / Hadith Number: 5392
Sayyar reported: 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.