Musannaf Ibn Abi Shayba 22:39

'Affan narrated to us, he said: Hammad bin Salamah narrated to us, he said: 'Abdullah bin Abi Bakr informed us: That Ziyad al-Numayri came with the reciters to Anas bin Malik. He said to him, "Recite." So he raised his voice, and he was loud-voiced. Anas uncovered the cloth from his face—and there was a black cloth upon his face—and he said, "What is this? This is not how they used to do." And whenever he saw something he disapproved of, he would uncover the cloth from his face.