Sahih Muslim
The Book on General Behaviour (Kitab Al-Adab)
Book Number: 025 / Hadith Number: 5350
Anas b. Malik reported that Allah's Messenger (may peace be upon him) had the sublimest character among mankind. I had a brother who was called Abd 'Umair. I think he was weaned. When Allah's Messenger (may peace he upon him) came to our house he saw him, and said: Abu 'Umair, what has the sparrow done? He (Anas) said that he had been playing with that.