There is nothing wrong in sleeping after Fajr. However, it was the practice of the Prophet and his Companions not to sleep after Fajr, as it is a time of blessing. Although it is permissible to spend the night in one’s affairs and to sleep after Fajr, we advise everyone to try to sleep early and tend to those affairs after Fajr, as it is a time of blessings and can better help you concentrate in your study. The blessing does not merely mean blessing in money and sustenance but it can be in knowledge as well as health, etc. Doing so, you will also be able to pray Fajr on time and never miss it due to late sleeping.
As for sleeping after `Asr, there is no evidence in the Qur’an or authentic hadith to prohibit it; and hence the general rule of permissibility of sleeping at these times is applicable.
Elaborating on this we’d like to cite for you the following Fatwa issued by Sheikh M. S. Al-Munajjid, a prominent Saudi Muslim lecturer and author, who states:
“As far as a person’s sleeping after praying Fajr is concerned, no text (of Qur’an or Sunnah) has been reported to indicate that this is prohibited, so the general principle applies (i.e., everything is permitted except that which has been expressly forbidden).
But the practice of the Prophet (peace and blessings be upon him) and his Companions after praying Fajr was to remain sitting in the place where they had prayed until the sun rose, as is reported in Sahih Muslim (1/463) in the hadith of Sammak ibn Harb, who said: I asked Jabir ibn Samurah, “Did you used to sit with the Messenger of Allah?” He said, “Yes, frequently. He would not get up from the place where he had prayed Subh (Morning Prayer) until the sun rose. When the sun rose, he would get up. They used to talk about things that had happened during the Jahiliyyah (pre-Islamic period), and they would laugh and smile.”
Also, the Prophet (peace and blessings of Allah be upon him) asked his Lord to bless his Ummah in the mornings, as is reported in the hadith of Sakhr al-Ghamidi, who said: “The Messenger of Allah (peace and blessings be upon him) said: ‘O Allah, bless my Ummah in the mornings.’ Whenever he sent out troops or an army, he would send them at the beginning of the day.” Sakhr was a trader, and he used to send out his caravans at the beginning of the day, and he did well as a result and
made money. [Reported by Abu Dawud, at-Tirmidhi and Ibn Majah, with a chain of transmitters in which there is unknown narrator; corroborating evidence is to be found in a hadith narrated by `Ali, Ibn `Umar, Ibn `Abbas, Ibn Mas`ud and others (may Allah be pleased with them all).]
For this reason, some of the salaf (early Muslims) disliked the idea of sleeping after Fajr. Ibn Abi Shaybah reported in his Musannaf (5/222, no. 25442) with an authentic chain of transmitters from `Urwah ibn al-Zubayr that he said: “Al-Zubayr used to forbid his children to sleep in the morning.” `Urwah said: “I do not hear of any man who sleeps in the morning but I lose interest in that person.”
In brief, people should make the most of this time which can bring many benefits in this world and in the Hereafter, but if a person sleeps at this time to gain strength to do his work, there is nothing wrong with this, especially if it is not easy for him to sleep at any other time of the day. Ibn Abi Shaybah reported in his Musannaf (5/223, no. 25454) from the hadith of Abu Yazid al-Madini who said: “`Umar came to Suhayb one morning and found him sleeping, so he sat down until he woke up. Suhayb said: ‘The Commander of the Faithful is sitting in his place and Suhayb is sleeping!’ `Umar said to him: ‘I did not like to disturb your sleep that could be beneficial for you.’”
As for sleeping after `Asr, this is also permitted; there is no authentic hadith from the Prophet (peace and blessings be upon him) to indicate that sleeping at this time is prohibited.
As for the words, “Whoever sleeps after `Asr and loses his mind as a result has no one to blame but himself,” which are attributed to the Prophet (peace and blessings be upon him), this is a false hadith and there is no proof that these words were uttered by the Prophet (peace and blessings be upon him).
Commenting on this false hadith, Sheikh al-Albani writes: “Marwan [ibn Muhammad al-Asadi] said: I said to Layth ibn Sa`d – when I saw him sleep after `Asr during the month of Ramadan – ‘O Abul-Harith! Why are you sleeping after `Asr when Ibn Lahi`ah has told us … (and he mentioned the false hadith)?’ Al-Layth said: ‘I do not give up something that is good for me because of the hadith of Ibn Lahi`ah from `Aqil!’ I am impressed by this answer of al-Layth, because it is indicative of understanding and knowledge, and no wonder, for he was one of the imams of the Muslims and well known jurists.”