In Qur'an, Allah (SWT) says:
Abu Hurairah reported:
The Messenger of Allah
Prophet Muhammad (PBUH) said,
“There are angels who take turns in visiting you by night and by day, and they all assemble at the dawn (Fajr) and the afternoon (`Asr) prayers. Those who have spent the night with you, ascend to the heaven and their Rubb, Who knows better about them, asks: `In what condition did you leave My slaves?’ They reply: `We left them while they were performing Salat and we went to them while they were performing Salat.”[Al-Bukhari and Muslim].
Jarir bin `Abdullah Al-Bajali (May Allah be pleased with him) reported: We were sitting with the Messenger of Allah (PBUH) when he looked at the full moon and observed,
“You will see your Rubb (Lord) in the Hereafter as you see this moon having no difficulty in seeing it. So try your best to perform the prayers before the rising of the sun and that before its setting.”
[Al-Bukhari and Muslim].
Abu Musa (May Allah be pleased with him) reported: Messenger of Allah (PBUH) said,
“He who The observes Al-Bardan (i.e., Fajr and `Asr prayers) will enter Jannah.”
[Al-Bukhari and Muslim].
Jundub bin Sufyan (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said,
“He who offers the dawn (Fajr) prayers will come under the Protection of Allah. O son of Adam! Beware, lest Allah should call you to account in any respect from (for withdrawing) His Protection.”[Muslim].
Abu Zuhair `Umarah Ruwaibah (May Allah be pleased with him) reported: I heard the Messenger of Allah (PBUH) saying:
“He who performs Salat (prayers) before the rising of the sun and before its setting, will not enter the Hell.”
At-Tirmidhee narrated upon the authority of Al Ghamdi that the Prophet (sallallaahu-alaihi-wasallam) said:
“O Allah bless my Ummah in its early rising!” and whenever he dispatched an expedition or army he sent them early at the beginning of the day. Sakhr was a merchant who always sent his merchandise early in morning thus, becoming wealthy (3). That is why we find the craftsmen and traders are particular about making good use of this time. Those who sleep up to the late morning have denied themselves the blessings of this early hour.
The Prophet (sallallaahu-alaihi-wasallam) said:
“Shaytaan ties three knots on the crown of any one of you in your sleep. He says upon each knot that he ties: “You have a long night before you, therefore sleep”. But if you wake up and mention Allah, Most Exalted in remembrance one knot will be untied. If you then make ablution another knot will be undone. If you then proceed to pray the last knot will be disentangled. Thus, you will feel in the morning energetic and in good spirits. Otherwise you will feel in a despicable state, lazy”.
[narrated by Maalik, Bukhaaree, Muslim and Abu Dawood]
Bukhari and Muslim and An-Nasaaee related on the
authority of Ibn Mas’ud (radiallaahu-anhu) that he said:
The case of a man who slept all the night up to sunrise (without waking up for Fajr) was related to the Prophet (sallallaahu-alaihi-wasallam) whereupon he said: “That was a man in whose ear Shaytaan has urinated”, or he said “in both his ears”.