Short answer
The Prophet ﷺ said the sun rises and sets between the two horns of Shaytan, at the moment when sun-worshippers bow to it. For that reason he forbade praying at sunrise, sunset and when the sun is at its height. Scholars explain the horns either literally or as a picture of Shaytan's power at those times.
In the Hanafi school, praying at sunrise, at the sun's zenith (zawal) or at sunset is forbidden, and a missed prayer made up at those times is not valid. The main exception is that day's Asr, which is still prayed at sunset, though delaying it so late is sinful. Voluntary prayer after Fajr until sunrise, and after Asr until sunset, is makruh tahrimi.
Other madhhabs
- Shafi'i
- Prayers that have a cause, such as a missed obligatory prayer, a funeral prayer or tahiyyat al-masjid, may be prayed at these times; only voluntary prayer without a cause is forbidden.
- Maliki
- A missed obligatory prayer may be made up at any time, including these times; voluntary prayer is not allowed then.
- Hanbali
- A missed obligatory prayer may be made up at any time, including these times; voluntary prayer without a cause is forbidden then, with a few exceptions.
Explanation
The Prophet ﷺ told Amr ibn Abasa to pray Fajr and then stop until the sun had risen, "for it rises between the two horns of Shaytan, and at that time the disbelievers prostrate to it" (Sahih Muslim). He gave the same reason for sunset. The point is clear: Muslims do not pray at the very moments people have bowed to the sun.
What are the horns? Scholars give two explanations. Many, such as al-Nawawi, take it on its apparent meaning: Shaytan places himself in line with the sun at those moments, so that the worship of the sun-worshippers falls toward him. Others say "horns" is a picture of his strength and the spread of his influence then, as Arabs speak of power. Both agree on the practical lesson.
From this come the forbidden times. Uqbah ibn Amir said there were three times the Prophet ﷺ forbade praying or burying the dead: as the sun rises until it is up, when it stands at its height until it passes, and when it begins to set until it has set. The full Hanafi rules are explained in What are the forbidden times for prayer?
People also search for another hadith: the Prophet ﷺ pointed toward the east and said trials would come from there, "from where the horn of Shaytan rises" (Sahih al-Bukhari). Hadith commentators explain that he was pointing east of Madinah, the direction from which many great trials of early Islam came. It is a warning about fitnah, not a statement about any people today.
The evidence
Sahih Muslim 832
Sahih... فإنها تطلع حين تطلع بين قرنى شيطان وحينئذ يسجد لها الكفار ...
"For it rises between the two horns of Shaytan, and at that time the disbelievers prostrate to it."
Gives the reason for not praying at sunrise.
Sahih Muslim 831
Sahih... ثلاث ساعات كان رسول الله صلى الله عليه وسلم ينهانا أن نصلي فيهن ...
"There were three times in which the Messenger of Allah ﷺ forbade us to pray."
Sets out the three forbidden times.
Sahih al-Bukhari 3279
Sahih... إن الفتنة ها هنا من حيث يطلع قرن الشيطان ...
"Trials are here, from where the horn of Shaytan rises."
The other hadith mentioning the horn of Shaytan, about trials from the east.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Chapter on the disliked times of prayer. Lists the three times when no prayer is valid and the times when voluntary prayer is disliked.
- al-Hidaya, Kitab al-Salah, chapter on the times when prayer is disliked. Gives the Hanafi rulings with the hadith of Uqbah ibn Amir.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.