Excellence and Secrets Of The Night Vigil Volume I Picture Oil lamp ...

In his Ihya, Imam Ghazzali explained that to qualify for Tahajjud, the
seeker [murid] must have slept and awaken. The Tahajjud prayers are
done when one awakes during the last part of the night before subuh. It
is usually part of the eleven raka’ats of witr or if the witr was completed
in the earlier part of the night, a continuation or as a separate night
prayer or even a Tahajjud prayers.
The Tahajjud Prayers
1. Your Intention (Niat) is: “I pray two raka'ats of witr (or the night
or the Tahajjud) Prayers supererogatory to Allah, the Exalted. Allah is
Great.”
There is a hadith which reported that no two witr prayers in one night.
You may have done witr after Isha or thereafter then the intention here
on is either for the ‘Night Prayers’ or “Tahajjud Prayers’.
2. Then recite the Opening Invocation [Doa Iftitah]:
“Allah is the Greatest, Praises and Thanks be to Allah, Transcendence is
Allah from early morning to late evening. I turn towards the One who
created the heavens and the earth. As a true believer, a Muslim, and I
am not of the polytheist. My prayers, devotion, life and my death are for
the God of the worlds, no partner has He and thus I am commanded to
obey, and I am among those who submit to Allah.”
In a hadith, it was narrated that when the Messenger of Allah s.a.w. got
up to pray at night for Tahajjud prayer, he uttered the takbir and then
said: “Transcendence are You, O Allah”; “Praise and Thanks be to
You”; “Glory be to Allah, the Lord of the Universe”.
He then said: “There is no god but Allah” three times; he then
said: “Allah is altogether great” three times:
And “I seek refuge in Allah, All-Hearing and All-Knowing from
the accursed devil, from his evil suggestion (hamz), from his puffing up
(nafkh), and from his spitting (nafth)” He then recited (the Qur'an).
From Abu Dawud, narrated by Abu Sa'id al-Khudri.
RL 16 - Part II - The Tahajjud Prayer