When the Prophet Mohammed S.A.W got up at night to offer the Tahajjud Namaaz (prayer), he used to say:
Allahumma lakal-hamd. Anta qaiyimus-samawati wal-ard wa man fihinna. Walakal-hamd, Laka mulkus-samawati wal-ard wa man fihinna. Walakal-hamd, anta nurus-samawati wal-ard. Walakalhamd, anta-l-haq wa wa’duka-l-haq, wa liqa’uka Haq, wa qualuka Haq, wal-jannatu Han wan-naru Haq wannabiyuna Haq. Wa Muhammadun, sallal-lahu’alaihi wasallam, Haq, was-sa’atu Haq. Allahumma aslamtu Laka wabika amantu, wa ‘Alaika tawakkaltu, wa ilaika anabtu wa bika khasamtu, wa ilaika hakamtu faghfir li ma qaddamtu wama akh-khartu wama as-rartu wama’a lantu, anta-l-muqaddim wa anta-l-mu akh-khir, la ilaha illa anta (or la ilaha ghairuka).
(O Allah! All the praises are for you, You are the Holder of the Heavens and the Earth, And whatever is in them. All the praises are for You; You have the possession of the Heavens and the Earth And whatever is in them. All the praises are for You; You are the Light of the Heavens and the Earth And all the praises are for You; You are the King of the Heavens and the Earth; And all the praises are for You; You are the Truth and Your Promise is the truth, And to meet You is true, Your Word is the truth And Paradise is true And Hell is true And all the Prophets (Peace be upon them) are true; And Muhammad is true, And the Day of Resurrection is true. O Allah ! I surrender (my will) to You; I believe in You and depend on You. And repent to You, And with Your help I argue (with my opponents, the non-believers) And I take You as a judge (to judge between us). Please forgive me my previous And future sins; And whatever I concealed or revealed And You are the One who make (some people) forward And (some) backward. There is none to be worshipped but you . Sufyan said that ‘Abdul Karim Abu Umaiya added to the above, ‘Wala haula Wala quwata illa billah’ (There is neither might nor power except with Allah).
The Prophet used to stand (in the prayer) or pray till both his feet or legs swelled. He was asked why (he offered such an unbearable prayer) and he said, “should I not be a thankful slave.”
He (the Prophet (p.b.u.h) ) used to get up for the prayer on hearing the crowing of a cock.
Quran ayat about praying in the night:
“Establish prayer at the decline of the sun [from its meridian] until the darkness of the night and [also] the Qur’an of dawn. Indeed, the recitation of dawn is everfrom [part of] the night, pray with it as additional [worship] for you; it is expected that your Lord will resurrect you to a praised station.” (Surah Isra, 17:78-79).
Hadiths about tahajjud:
Abu Hurairah reports that the Messenger of Allah (saws) 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?”[ Bukhari and Muslim.]
Abdullah ibn `Amr reports that the Prophet (saws) said: “The most beloved fast to Allah is the fast of (Prophet) Dawood (a.s.). And the most beloved prayer to Allah is the prayer of (Prophet) Dawood (a.s.). He (Prophet Dawood (a.s.)) would sleep half of the night and then pray during the next third of the night and then sleep during the last sixth of thehe would fast one day and not fast the next.”[ Bukhari and Muslim.]
Abu Hurayra (Allah be pleased with him) reports that the Messenger of Allah (blessings and peace be upon him, his family, and companions) said, “The best prayer after the obligatory prayers is the night prayer.”[Muslim]
Abd Allah ibn Salam (Allah be pleased with him) reports that the Messenger of Allah (blessings and peace be upon him, his family, and companions) said, “O people! Spread the salams, feed others, maintain family ties, and pray at night when others sleep and you will enter Heaven safely.”[Tirmidhi, Hakim]