A large number of the commentators have said that deeds done on that night are better than the deeds of 1,000 months which do not contain a Night of the Decree. Ka`b al-Ahbar said -- may God be well pleased with him:
"There was a righteous king among the Bani Isra'il. God revealed to their Prophet: "Tell him to wish for something." He said: "I wish to strive in the way of God with my possessions and my offspring." God gave him one thousand children. He began to prepare each child for battle until that child died as a martyr, whereupon he prepared the next one, and so forth until they were all killed in a period of 1,000 months. Then the king himself entered the fray and was killed. The people said: "No-one will ever be able to attain to his merit." And (now) God revealed this sura (The Decree)."
Al-Waqidi said: "It is the first sura revealed in Madina." Najm al-Din al-Nasafi, however, says: "Eighty-five suras were revealed in Mecca, the first being al-Fatiha and the last "Woe unto the Defrauders" (sura 83); and twenty-nine were revealed in Madina, the first being "al-Baqara" (sura 2) and the last "al-Ma'ida" (sura 5)."
Abu Bakr al-Warraq said: "Solomon's kingdom was five hundred months, and Dhu al-Qarnayn's kingdom was five hundred months, and God has made the deeds done during that night outweigh both kingdoms."
I saw in Rawd al-afkar (The Meadows of Reflections) that one day the Prophet (s) mentioned four men who had who had worshipped God for eighty years, not disobeying him for one blink of an eye. The Companions were seized by wonder at this, whereupon Gabriel came to him and brought him this sura so that the Prophet (s) and the Companions became happy.
The scholars differ concerning the designation of the Night of the Decree. Most say that it falls on the twenty-seventh of Ramadan. Whoever prays on that night four rak`at (prayer-cycles) in which he recites al-Fatiha, "Rivalry in worldly increase distracteth you" (sura 102) once, and "Say He is God: One" (sura 112) three times, Allah will make the throes of death easy for him, remove from him the punishment of the grave, and give him four pillars of light on top of each of which rest 1,000 palaces.
Al-Shafi`i said -- may God be well pleased with him: "The strongest reports I have is that it falls on the twenty-first." The author of Tanbih al-ghafilin (Abu al-Layth al-Samarqandi, d. CE 983 CE) reportedly said it is not confined to the last ten nights of Ramadan, but al-Rafi`i rejected this opinion. What I did see in the "Tanbih" is that he said that the letters which form "The Night of the Decree" are nine (la-y-la-t-a-l-qa-d-r), and God mentioned it three times in the sura: 9 x 3 = 27, which is an indication that it falls on the twenty-seventh.
This is also the opinion of Ibn `Abbas, who adduced the fact that God created seven heavens, seven earths, seven seas, and seven days; and that He created us from seven elements and nourished us with seven kinds of food, according to His saying (80:27-31):
"And we cause the grain to grow therein"-- this is (1)wheat and (2)barley --"and (2) grapes, and (3) reeds"-- that is, canes --"and (4) olives and (5) dates, and garden-closes of thick foliage"-- orchards with great trees --"and (6) fruits"-- such as figs --"and (7) grasses"-- that is, the vegetation which animals eat.
And finally, (Ibn `Abbas adduces) that He ordered us to prostrate upon hearing seven verses. All this is discussed in the chapter on trust (al-amana).
Blessings and Peace on the Prophet, his Family, and his Companions