Qadr (قدر), in Arabic, means measure and limit or value of something or destiny.^[8] Some reasons have been offered for its naming:

• It is said that it was called al-Qadr because the annual destiny of every person will be determined by God.^[9]
• Some say that if one stays awake at this night praying, reading Quran, or repenting, one will reach a high state.^[10]
• Some have said that it was called al-Qadr because it is a grand and high-value night.^[11]

Other names such as “Laylat al-‘Azama” (Arabic: ليلة العظمة; night of the greatness) and “Laylat al-Sharaf” (Arabic: ليلة الشرف; lit. ‘night of the honor‘) have also been used.^[12]

Some commentators believe that the Quran was revealed to Muhammad twice;

• the ‘immediate revelation’ happening on the Laylat al-Qadr and
• ‘gradual revelation’ over 23 years.

The Quran uses the word anzal (انزل) which justifies ‘the immediate revelation’, according to Allamah Tabatabai.^[13] Some others believe that the revelation of Quran occurred in two phases, with the first phase being the revelation in its entirety on Laylat al-Qadr to the angel Gabriel (Jibril in Arabic) in the lowest heaven, and then the subsequent verse-by-verse revelation to Muhammad by Gabriel.^[3] The revelation started in 610 CE at the Hira cave on Mount Jabal al-Nour in Mecca. The first Surah that was revealed was Sūrat al-ʿAlaq (in Arabic العلق).^[14] During Muhammad’s first revelation, the first five verses of this Surah, or chapter, were revealed.^[15]

Muhammad would usually practice spiritual retreat (Iʿtikāf) during the last ten days of Ramadan, awaiting the Night of Power, fasting and praying throughout the night, and abstaining from sexual relations. He urged his followers to do the same. According to one hadith, Muhammad said: “Whoever stands [in prayer] during the Night of Power out of belief and seeking reward, his previous sins are forgiven.” (Sahih al-Bukhari 1901)^[16][17]

A specific date of Laylat al-Qadr is not mentioned in the Quran.^[18][19] Muhammad said God told him the exact date of Laylat al-Qadr in a dream, that he went to tell his companions about that date, and that he saw two people fighting and was caused to forget the date (by God).^[20]

According to the Islamic calendar, an Islamic day begins at Maghrib prayer (sunset). The Night of Power extends from Maghrib to Fajr prayer (dawn).^[21]

Sunni Muslims believe that Laylat al-Qadr most likely occurs among the odd-numbered nights of the last ten nights of Ramadan (21st, 23rd, 25th, 27th or 29th). Some scholars opine that if a Friday night occurs on an odd numbered night, the night is likely to be Laylat al-Qadr.

The night is not comparable to any others in view of Muslims^[25] and according to a tradition, the blessings due to the acts of worship during this night cannot be equaled even by worshipping throughout an entire lifetime. The reward of acts of worship done in this one single night is more than the reward of a thousand months of worship.^[40]

Surah Al-Qadr of the Quran is about Laylat al-Qadr:^[3][25]

We have indeed revealed this (Message) in the Night of Decree:

And what will explain to thee what the Night of Decree is?

The Night of Decree is better than a thousand months.

Therein come down the angels and the Spirit by Allah’s permission, on every errand:

Peace!… This until the rise of dawn!

— Surah Al-Qadr 97:1-5

Devout Muslims practice spiritual retreat (Iʿtikāf) during the last ten days of Ramadan, awaiting the Night of Power, fasting and praying throughout the night, and abstaining from sexual relations. Some Muslims practice Iʿtikāf by staying at a mosque throughout the ten days.