Musannaf Ibn Abi Shayba 3:4985

Al-Fadl ibn Dukayn narrated to us, from Mis'ar, from 'Ubayd, from al-Hasan, from Ibn Mughaffal, who said: Abu Mas'ud saw a man praying at the rising of the sun, or at the time in which prayer is disliked, so he ordered a man, and he forbade him.