Umar on prayer at sunrise and the shaytan's horn

Malik relates from Ibn Umar that Umar ibn al-Khattab (may God be pleased with him) used to say: "do not seek your prayer at sunrise or sunset, for the shaytan's horns rise with the sunrise and set with the sunset," and he would beat people for praying then ¹ Muwatta 589.

In Umar's saying the prohibited prayer-times are tied to the shaytan's horn; at sunrise and sunset the sun is where the shaytan holds sway, which is why prayer was forbidden in those hours ¹. The Muwatta cites parallels of this prohibition in the chapters of prayer-times ¹.

This is among the reports of the Companions' dealings with the shaytan in the Muwatta; this browser shows it in the devils section ¹.