There are specific times for the five daily obligatory prayers. With regard to supererogatory and voluntary prayers, it is permissible to offer them at any time, apart from the fact that the Prophet (blessings and peace of Allah be upon him) forbade praying at certain times, which include what is mentioned in this hadith, namely the time when the sun is rising and the time when it is setting. The Prophet (blessings and peace of Allah be upon him) said: “Do not aim to offer your prayer when the sun is rising or setting.” In other words, do not seek out these two times to pray. The reason for that – as mentioned in other reports – is that the sun rises between the two sides of the head of a devil, or the side of the head of the Shaytan rises with it, and because some of the disbelievers used to prostrate to the sun and pray to it at these two times. Therefore it is prohibited to pray at these two times, in order to differ from these disbelievers. This prohibition is understood to refer to voluntary prayers at these times. In the case of one who has an excuse for not having caught up with the obligatory prayer at the beginning of its time, he may pray at the end of its time and catch up with the prayer before the sun rises and before it sets, as it says in the hadith narrated by al-Bukhari: “Whoever catches up with one rak‘ah of Fajr before the sun rises has caught up with Fajr.” Or it may be that the prohibition is on praying deliberately at the time of sunrise or sunset. However, if it is not done deliberately – as in the case of one who wakes up or remembers after having forgotten – he may pray (at those times) and there is no blame on him..