Allah (may He be Exalted) says: "Therein descend the angels and the Rûh [Jibrîl (Gabriel)] by Allâh's Permission with all Decrees, * (All that night), there is Peace (and Goodness from Allâh to His believing slaves) until the appearance of dawn." [Surat Al Qadr: 4 - 5].
Zirr ibn Hubaysh (may Allah be merciful with him) narrated: "I heard Ubayy ibn Ka`b saying: And it was said to him: `Abdullah ibn Mas`ud said: whoever prays Qiyam for a year will attain Laylat-ul-Qadr: Ubayy said: 'By Allah, besides Whom there is none worthy of worship! It is in Ramadan' - and he swore with no reservation - 'and by Allah, I know which night it is! It is the night which the Messenger of Allah (peace be upon him) commanded us to spend in prayer; it is the night of the twenty-seventh, and its sign is that the sun rises that day bright with no rays.'" 
In another narration of Ibn Hibban: "And its indication is that the sun rises bright on that day without rays as if it is small and a little bit yellowish."
1- Al Qady `Iyad said in the explanation of the saying of Ubayy: It has two meanings: A- It was a description to the morning of that night which the Prophet (peace be upon him) told as Laylat-ul-Qadr and made it one of the signs of that night not every night of Decree. He also told them that he prostrated in water and mud during Laylat-ul-Qadr.
2- It is a permanent quality to that night. It was said that the sun is blocked by the rising angles to the sky who come down and go up until dawn. And Allah knows the best.
Ibn Mas`ud (may Allah be pleased with him) narrated that the Messenger of Allah (peace be upon him) said: "Laylat-ul-Qadr exists in the half of the last seven days of Ramadan when the Sun rises clear with no ray. Ibn Mas`ud said: I looked at it and found it as the Messenger of Allah said." [Reported by Ahmad]
Abu Hurayrah (may Allah be pleased with him) narrated that the Messenger of Allah (peace be upon him) said in Laylat-ul-Qadr: "It is the seventh or ninth night where angles at that night on earth are more than the number of pebbles." [Reported by Ahmad]
`Ubadah ibn As-Samit (may Allah be pleased with him) narrated that the Messenger of Allah (peace be upon him) said: "The sign of the Laylat-ul-Qadr (the Night of Decree) is clearness i.e., yellow and bright as if it has a bright moon and calm i.e., has no heat or cold, and it is not permissible that the earth is inflicted by falling stars on that night. Also, the sun rises clear and bright on the morning like a full moon and Satan does not exist on that night." [Reported by Ahmad]
Jabir (may Allah be pleased with him) narrated that the Messenger of Allah (peace be upon him) said: "I have been shown Laylat-ul-Qadr (the Night of Decree), but have forgotten its date, but it is in the last ten nights of Ramadan. It is clear, not hot not cold, as if it has a moon that displays its stars. Its devils do not come out [during that night] until its dawn comes." [Reported by Ibn Khuzaymah and Ibn Hibban].
Ibn `Abbas (may Allah be pleased with him) narrated that the Prophet (peace be upon him) said about Laylat-ul-Qadr (the Night of Decree): "It is a clear night, not hot nor cold, and the sun rises on the morning as a weak reddish." [Reported by Ibn Khuzaymah].
Benefits and rulings:
These texts denote that Laylat-ul-Qadr has sings which are:
The first sign is: Frequent descent of angles on that night preceded by Gabriel (peace be upon him) to bear witness for praying people in their masjids to the extent that angels are more than the number of pebbles; and this sign does not show to people.
The second sign is: Peace and safety is found on that night because of the righteous actions of people in obedience to Allah (Glory be to Him).
The third sign is: The sun rises in that morning clear with no ray and the reason for that is as scholars said: Angles ascend to the sky blocking the light of the sun with their wings and lights.
The fourth sign is: One of its signs is: It is a clear and quiet night, not cold nor hot, and that is relative according to the nature of the country, and the meaning is: The climate is different from the previous and following nights.
The fifth sign is: Satan does not come with the sun of the next morning because the sun rises between the horns of Satan except that night.
Most of these signs are not clear to people except after the elapse of that night. The benefit of that is: People should thank their lord for catching it and other would regret for losing it, making up their minds to catch it the next year.
These signs are applied to every Laylat-ul-Qadr not those night which came at the time of the Prophet (peace be upon him).
 Reported by Muslim (1 / 525), the book of Salah of travelers, chapter on awakening the desire for performing Qiyam in Ramadan i.e., Tarawih No. (762).
 Reported by Ahmad (1 / 406) and Ibn Abu Shaybah (2 / 250), and was graded as authentic by Ahmad Shakir (3857).
 Reported by At-Tyalisy (2545) and Ahmad (2 / 519).
Ibn Khuzaymah ranked it as authentic (2194), and Ibn Kathir said in his exegesis (Tafsir) (4 / 535): Its chain of transmission is good. Al Haythamy said: Reported by Imam Ahmad, Al Bazzar, and At-Tabarany in Al Mu`jam Al Awsat, and its narrators are trustworthy (3 / 175 - 176). Al Albany graded it as good in his commentary on Sahih Ibn Khuzaymah (3 / 332) and in As-Silsilah As-Sahihah (2205).
 Reported by Ahmad (5 / 324), At-Tabarany in Musnad Ash-Shamiyyin (1119), Ad-Diya' in Al Mukhtarah (342), Al Haythamy said in Az-Zawa'id (3 / 175): Its narrators are trustworthy.
 Reported by Ibn Khuzaymah (2190) and Ibn Hibban (3688), and Al Albany graded it as authentic by similar narrations.
 Reported by Ibn Khuzaymah (2192), and Al Albany graded it as authentic by similar narrations.
 See: Ikmal Al Mu`allim (4 / 148), the commentary of An-Nawawy on Sahih Muslim (8 / 65), Al Mufhim (2 / 391), Ad-Dibaj (3 / 259), and Faydul-Qadir (5 / 396).
 Al Qurtuby mentioned that it is more entitled, Al Mufhim (2 / 391).
Please write: COMMENT in this box to verify that you are human