Musannaf Ibn Abi Shayba 3:3940

Muhammad ibn Bishr narrated to us, he said: Sa’id narrated to us, from Qatadah, from Anas, from the Prophet (may Allah bless him and grant him peace), that he said: "What is the matter with people who raise their eyes toward the sky during their prayer?" He was severe regarding that, until he would say: "They must desist from that, or their eyesight will surely be snatched away."