Qiyam means 'standing' and ‘Qiyam al-Layl’ means 'standing at night'. In the Shari’ah term both terms refer to 'the voluntary night prayer.
If one divides the night into six parts, the fourth and fifth part are the best for prayer. If divided in half, the second half is best. If into thirds, the middle part is best. With this said Tahajjud is offered after ‘Isha and before Fajr.
The Excellence of Qiyam al-Layl:
Many Qur'anic verses speak about the excellence of Qiyam and the merits of those people, who perform Qiyam al-Layl on a regular basis, for example, Allah describes the believers who deserve Jannah saying:
“They (the believers) forsake their beds, to invoke their Lord in fear and hope; and they spend out of what We have bestowed on them.” [Soorah as-Sajdah (32): 16] “They (the pious) used to sleep but little at night.” [Soorah ath-Thariyat (51): 17]
Those who regularly perform the tahajjud prayers are the Righteous and are more deserving of Allah's bounty and mercy. Allah says: "Lo! Those who keep from evil will dwell amid gardens and watersprings, taking that which their Lord gives them. For, lo, they were doers of good. They used to sleep but little of the night and before the dawning of each day would seek forgiveness.''
Also, numerous Ahadith add to this subject, narrated Abu Hurayrah (radhi allahu anhu): “The Messenger of Allah (sallallahu alaihi wa-sallam) said:
“The best prayer after those prescribed is (the prayer performed) in the depth of night.” [Sahih Muslim and Musnad Ahmad]
Protection from Shaitan:
Abu Hurayrah (radhi allahu anhu) reported that the Messenger of Allah (sallallahu alaihi wa-sallam) said:
“When one of you goes to sleep, Shaitaan ties three knots over the rear of his head, blowing into each knot, 'You have a long night, so sleep on.” If he wakes up and mentions Allah, one knot loosens. If he makes wudhu (ablution for prayer), another knot loosens and if he prays, the third knot loosens and he becomes lively and good-natured; otherwise he gets up ill-natured and lazy.” [Sahih al-Bukhari and Sahih Muslim]
Acceptance of Supplication:
Abu Hurayrah (radhi allahu anhu) reported that the Messenger of Allah (sallallahu alaihi wa-sallam) said:
“Our Lord descends every night to the lowest heaven, when only one third of the night has remained. He says: “Who will invoke Me, so that I may give him? Who will seek My forgiveness, so that I may forgive him.” [Sahih al-Bukhari and Sahih Muslim]
Mercy from Allah:
Abu Hurayrah (radhi allahu anhu) reported that the Messenger of Allah (sallallahu alaihi wa-sallam) said
“May Allah have mercy on a man who wakes up at night, prays and wakes his wife to pray; and if she refuses, he sprinkles water on her face. And may Allah have mercy on a woman who wakes up at night, prays, and wakes her husband to pray and if he refuses, she sprinkles water on his face.” (hasan) by Shaikh al-Albani (Abu Dawud)
The Excellence of Qiyam in Ramadan:
Many Ahadith describe the excellence of Qiyam particularly in Ramadan, some of them are:
Forgiveness of sins:
Abu Hurayrah (radhi allahu anhu) reported:
“Allah's Messenger (sallallahu alaihi wa-sallam) encouraged the people, without making it an absolute command, to perform Qiyam during Ramadan. He (sallallahu alaihi wa-sallam) used to say: “Whoever stands (in Qiyam) in Ramadaan out of faith and expectation (of Allah's Reward), all his previous sins will be forgiven.” [Sahih al-Bukhari and Sahih Muslim]
Etiquettes of Late Night Prayer
The following acts are sunnah for one who wishes to perform the tahajjud prayers.
1) Upon going to sleep, one should make the intention to perform the tahajjud prayers. Abu ad-Darda' relates that the Prophet sallallahu alehi wasallam said: "Whoever goes to his bed with the intention of getting up and praying during the night, and sleep overcomes him until the moming comes, he will have recorded for him what he had intended, and his sleep will be a charity for him from his Lord." This is related by an-Nasa'i and ibn Majah with a sahih chain.
2) Upon waking, one should wipe one's face, use a toothstick, and look to the sky and make the supplication which has been reported from the Prophet sallallahu alehi wasallam: "There is no God but Thee, Glory be to Thee, I seek forgiveness from You for my sins, and I ask for your mercy. O Allah, increase my knowledge and let my heart not swerve after You have guided me, and bestow mercy upon me from Thyself. All praise be to Allah who has given us back life after our death and unto Him is the resurrection."
3) Then, one should recite the last ten 'ayat of al-'Imran, starting with, "Lo! In the creation of the heavens and the earth and [in] the difference of night and day are tokens (of His sovereignty) for men of understanding." Then one should say, "O Allah, to You belongs the praise. You are the Light of the heavens and the earth and what is therein. And to You belongs the praise. You are the truth and Your promise is true. And the meeting with You is true. And the paradise is true. And the Fire is true. And the prophets are true. And Muhammad is true. And the Hour is true. O Allah, to You have I submitted. And in You have I believed. And in You have I put my trust. And to You have I turned. And by You I argue. And to You do I turn for my decisions. Forgive me of my former and latter sins, and those done in private and those done in public. You are Allah, there is no God besides Thee."
One should begin Qiyam al-Layil with two quick rak'at and then one may pray whatever one wishes after that. 'Aishah says: "When the Prophet prayed during the late-night, he would begin his prayers with two quick rak'at." Both of these reports are related by Muslim.
One should wake up one's family for tahajjud
Umm Salamah narrates that the Prophet sallallahu alehi wasallam got up during the night and said: "Glory be to Allah. What trials are descended with the night. And what has descended of treasures. Who will waken the lady occupants of the rooms (i.e., his wives) for prayers; how many a well dressed in this world will be naked in the hereafter." This is related by al-Bukhari
Al-Bukhari and Muslim record that the Messenger of Allah asked 'Ali and Fatimah: "Do you not pray [during the night]?" 'Ali said: "O Messenger of Allah, we are in Allah's hands. If He wishes to make us get up, we get up." The Prophet turned away when he said that. Then, they could hear him striking his thigh and saying: "Verily, man disputes a lot." This is related by al-Bukhari and Muslim.
One should stop praying tahajjud and sleep if one becomes very sleepy
'Aishah reports that the Messenger of Allah said: "When one of you gets up during the night for prayer and his Qur'anic recital becomes confused to the extent that he does not know what he says, he should lie down." This is related by Muslim.
Anas narrates that the Messenger of Allah entered the mosque and saw a rope stretching between two posts. He asked: "What is this?" The people told him that it was for Zainab [bint Jahsh] who, when she became tired or weary, held it (to keep standing for the prayer). The Prophet said: "Remove the rope. You should pray as long as you feel active, and when you get tired or weary, you should lie down to rest." This is related by al-Bukhari and Muslim.
One should not overburden one's self with the night prayer and should only pray it to the extent that is reasonable, and not leave that practice unless there is some great need to do so. 'Aishah reports that the Messenger of Allah said: "Do (good) deeds according to your capacity, for by Allah, Allah does not weary from giving rewards unless you get tired of doing good deeds." This is related by al-Bukhari and Muslim.
Al-Bukhari and Muslim also relate from 'Aishah that the Messenger of Allah was asked: "What is the most loved deed to Allah?" He answered: "One that is performed constantly even if it is a small deed." And Muslim recorded that 'Aishah said: "The Messenger of Allah was constant in his deeds, and if he did something, he would do it consistently."
Al-Bukhari and Muslim also record, on the authority of 'Abdullah ibn Mas'ud, that it was mentioned to the Prophet sallallahu alehi wasallam that a man slept until the morning. [ThereuponJ he said: "Satan has urinated into the ears of that person." They also record from Salim ibn 'Abdullah ibn 'Umar, from his father, that the Messenger of Allah said to his father, "Abdullah would be a good man if he would pray the tahajjud prayers." Salim said: "After that, 'Abdullah would not sleep during the night save for a small amount at a time."
Best time for tahajjud
It is best to delay this prayer to the last third portion of the night. Abu Hurairah reports that the Messenger of Allah said: "Our Lord descends to the lowest heaven during the last third of the night, inquiring: 'Who will call on Me so that I may respond to him? Who is asking something of Me so I may give it to him? Who is asking for My forgiveness so I may forgive him?"' This is related by the group.
'Amr ibn Abasah reports that he heard the Prophet say: "The closest that a slave comes to his Lord is during the middle of the latter portion of the night. If you can be among those who remember Allah, the Exalted One, at that time then do so." This is related by al-Hakim who grades it sahih according to Muslim's standards, and at-Tirmizhi calls it hasan sahih. AnNasa'i and Ibn Khuzaimah also recorded it.
Abu Muslim asked Abu Zharr: "Which late-night prayer is the best?" He said: "I asked the Messenger of Allah the same that you asked me and he said, 'The (one done during) middle of the latter half of the night, and very few do it.'" This is related by Ahmad with a good chain.
'Abdullah ibn 'Amr reports that the Prophet said: "The most beloved fast to Allah is the fast of David. And the most beloved prayer to Allah is the prayer of David. He would sleep half of the night and then pray during the next third of the night and then sleep during the last sixth of the night. And he would fast one day and not fast the next." This is related by the group except at-Tirmizhi.
The number of rak'at to be performed during tahajjud: The tahajjud prayer does not entail a specific number of rak'at which must be performed nor is there any maximum limit which has to be performed. It would be fulfilled even if one just prayed one rak'ah of witr after the obligatory night prayer.
Samurah ibn Jundub says: "The Messenger of Allah ordered us to pray during the night, a little or a lot, and to make the last of the prayer the witr prayer." This is related by at-Tabarani and al-Bazzar.
Iyas ibn Mu'awiyyah al-Mazni reports that the Prophet sallallahu alehi wasallam said: "The night prayer should certainly be performed even if it is for the length of time that it takes one to milk a sheep. And whatever is after the obligatory 'isha is of the tahajjud." This is related by at-Tabarani, and all of its narrators are trustworthy save Muhammad ibn Ishaq.
Ibn 'Abbas also narrates that the Prophet ordered them and encouraged them to make the tahajjud prayer to the extent that he said: "You should perform salatul layil even if it is just one rak'ah." This is related by atTabarani in al-Kabir and al-Awsat.
Note: Sources: www.sunnipath.com