Musnad Ahmad 32:48

Isma'il narrated to us, 'Abd al-'Aziz ibn Suhayb narrated to us, from Anas ibn Malik, who said: When the Messenger of Allah (may Allah bless him and grant him peace) arrived in Medina, Abu Talha took my hand and set off with me to the Messenger of Allah (may Allah bless him and grant him peace). He said: "O Messenger of Allah, Anas is a clever boy, so let him serve you." He said: "So I served him during travel and at home. By Allah, he never said to me regarding something I had done: 'Why did you do this like this?' Nor did he say regarding something I had not done: 'Why did you not do this like this?'"