Below are Ahadees related to Celebration of Shab e Barat all of these Hadees are certified and are taken from Sahih Satta ( The 6 Authentic Books of Hadees).
Shab e Baraat is not a Bidah it is a night of Blessing it should be celebrated sacredly.
1) “Surely, We have sent it (the Holy Qur’an) down in a blessed night. Surely, We are the Warner. In this (night) judgment is given on all matters of wisdom (separately) by Our Command.” (Sura ad-Dukhan, 44:3-5)
Imam Qurtubi and Imam Jalal-ud-Din Suyuti hold that the verses refer to Laylatun Nisf min Shaban or Shab-e-Barat.
2) A tradition narrated by Aisha, the mother of the faithful: “The Prophet did not fast in any month more than Shaban.” (Sahih Bukhari)
3) Narrated by Aisha (r.a), I missed Allah's Messenger during the night and found him in al-Baqui'. He said: Were you afraid that Allah and His Messenger would deal unjustly with you? I said: Allah's Messenger, I thought that you had gone to some of your other wives. He (the Prophet) said: Verily Allah, the Exalted and Glorious, comes down to the heaven of the world in "the middle night of Sha'ban" and forgives sins even more abundant than the hair of the goats of Kalb. [Sunan Tirmidhi Volume 001, Hadith Number 670, Ibn Maja Volume 002, Hadith Number1379]
4)A third tradition of Hazrat Aisha, the truthful, states that the Holy Prophet asked: “Do you know what happens this night?” meaning the middle night of Shaban (that is, Shab-e-Barat). She submitted: “O Allah’s Messenger, what happens in it?” He replied: “In it record is made of every human being who will be born, and of every human being who will pass away this year. In it their deeds are taken up to heaven and in it their provisions are sent down.” (Baihaqi).
It is narrated by Hazrat Ali (RA) in which he tells that Prophet Muhammad (PBUH) said:
“When it is the fifteenth night of Shaban observe prayer during the night and observe fast during the day; for Allah descends to the heaven of the world as the sun sets and says: Is there anyone to seek forgiveness so that I should forgive him? Is there anyone to seek sustenance so that I should provide him? Is there anyone in trouble so that I may relieve him? And so on and so forth, until the dawn breaks.” (Ibn Majah)
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