Musnad Ahmad 32:397

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Sayyar, who said: I was walking with Thabit al-Bunani, and he passed by some young boys and greeted them. And he narrated that he [Thabit] was walking with Anas, and he passed by some young boys and greeted them. And Anas narrated that he was walking with the Messenger of Allah, peace and blessings of Allah be upon him, and he passed by some young boys and greeted them.