Muwatta Malik #522

Yahya related to me from Malik from Zayd ibn Aslam from Ata ibn Yasar from Abdullah as-Sunabihi that the Messenger of Allah, may Allah bless him and grant him peace, said, "The sun rises and with it is a horn of Shaytan and when the sun gets higher the horn leaves it. Then when the sun reaches the meridian the horn joins it and when the sun declines the horn leaves it, and when the sun has nearly set it joins it again." The Messenger of Allah, may Allah bless him and grant him peace, forbade prayer at these times.