Musannaf Ibn Abi Shayba 3:2206

Ibn ‘Ulayyah narrated to us, from Ayyub, from ‘Ata’ al-Khurasani, who said: When the mosque was built during the era of ‘Uthman, they placed a pinnacle (or turret) on its roof. When a person entering would enter, his gaze would be raised toward it. This reached ‘Uthman, so he ordered it, and it was removed.