Anas radiyallahu anhu says, Rasoolullah sallallahu alaihe wasallam used to associate with us and joke. I had a younger brother. Rasoolullah sallallahu alaihe wasallam said to him, "Aba Umayr, what happened to the Nughayr?" (ID)
English reference (ID): Book 35, Hadith 226 (ID)
Arabic reference (ID): Book 36, Hadith 236 (ID)