What is tahajjud prayer?

A prayer the Quran names

The word tahajjud comes from the Quran itself, where Allah told the Prophet ﷺ to rise at night:

The Prophet ﷺ said: "The best prayer after the obligatory prayers is the prayer at night" (Sahih Muslim 1163). He prayed it so long that his feet swelled, and when asked why, he said, "Should I not be a grateful servant?" (Sahih al-Bukhari 1130).

Why the last third of the night

The Prophet ﷺ said that Allah descends to the lowest heaven every night when the last third remains, and asks: who is calling on Me so I may answer, who is asking so I may give, who is seeking forgiveness so I may forgive (Sahih al-Bukhari 1145). That makes it one of the best moments for dua. See What are the best times to make dua?

To find the last third, take the time from Maghrib to Fajr and divide it by three. If Maghrib is 6:00 pm and Fajr is 6:00 am, the last third starts around 2:00 am. In summer in northern Europe the nights are short, so it may be only an hour or so.

How to pray it

• Sleep first, even briefly. Most scholars say night prayer after sleeping is what is called tahajjud; any prayer after Isha is still qiyam al-layl (night prayer).
• Wake up, say the waking-up dhikr, and make wudu. See What should I say when I wake up?
• Pray in twos: 2, 4, 8 rakat or more, with salam after every two. The Prophet ﷺ usually prayed 11 in total including witr.
• Finish with witr if you didn't pray it before bed.
• Make dua in sujood and after the salam, in your own words.

Starting small

You don't need to stand for hours. Waking 15 minutes before Fajr for two rakat is real tahajjud. Consistency matters more than length, and a little done regularly is loved by Allah. Ramadan, especially the last ten nights, is a great time to start the habit. See What are the last ten nights of Ramadan?