Laylat al-QadrHadith - Al-Tirmidhi #1962, Narrated AbuHurayrah [Ahmad and Nasa'i transmitted it.]
Allah's Messenger said, "Ramadan, a blessed month, has come to you during which Allah has made it obligatory for you to fast. In it the gates of Heaven are opened, the gates of al-Jahim are locked, and the rebellious devils are chained. In it Allah has a night which is better than a thousand months. He who is deprived of its good has indeed suffered deprivation."
Hadith - Al-Tirmidhi #2092, Narrated AbuBakrah [Tirmidhi transmitted it.]
AbuBakrah heard Allah's Messenger say, "Seek it (meaning Laylat al-Qadr), on the twenty-first, twenty-third, twenty-fifth, twenty-seventh, or on the last night."
Hadith - Al-Tirmidhi #2096, Narrated Anas ibn Malik [Bayhaqi transmitted it in Shu'ab al-Iman.]
Allah's Messenger said that when Laylat al-Qadr comes, Gabriel descends with a company of angels who invoke blessings on ever who is standing or sitting and remembering Allah, who is Great and Glorious. Then when their festival day comes, i.e. the day when they break their fast, Allah speaks proudly of them to His angels saying, "My angels, what is the reward of a hired servant who has fully accomplished his work?" They reply, "Our Lord, his reward is that he should be paid his wage in full." He says, "My angels, My male and female servants have fulfilled what I have made obligatory for them, and then have come out raising their voices in supplication. By My might, glory, honour, high dignity and exalted station, I shall certainly answer them." Then He says, "Return, for I have forgiven you and changed your evil deeds into good deeds." He said that they then returned having received forgiveness.
Hadith - Sahih Bukhari, Vol. 3, Book 31, #125, Narrated Abu Huraira
The Prophet said, "Whoever established prayers on the night of Qadr out of sincere faith and hoping for a reward from Allah, then all his previous sins will be forgiven; and whoever fasts in the month of Ramadan out of sincere faith, and hoping for a reward from Allah, then all his previous sins will be forgiven."
Last Ten Nights of Ramadan
Hadith - Al-Tirmidhi #2102, Narrated Anas ibn Malik; Ubayy ibn Ka'b
The Prophet was accustomed to engage in private devotion in the mosque during the last ten nights of Ramadan; but one year he omitted it and he engaged in it for twenty nights the next year.
[Tirmidhi transmitted it, and AbuDawud and Ibn Majah transmitted it from Ubayy ibn Ka'b.]
Hadith - Al-Tirmidhi #2107, Narrated Abdullah ibn Umar [Ibn Majah transmitted it.]
When the Prophet observed a period of private devotion in the mosque, his bedding was placed for him, or a couch was put down for him, behind the column of repentance.