Musnad Ahmad 32:1742

Ali ibn Ishaq narrated to us, Abdullah informed us, he said: Humayd al-Tawil informed us, from Anas ibn Malik, who said: "I served the Messenger of Allah, may Allah bless him and grant him peace, for nine years. He never once said to me regarding anything I had done: 'Why did you do that?' nor 'How evil is what you have done.'"