It is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, that the Messenger of Allah, peace and blessings be upon him, said: Whoever stands (in prayer, i.e., Tarawih) during the nights of Ramadan with faith and seeking reward, his previous sins will be forgiven.
Hadith Referenceاللؤلؤ والمرجان / كتاب صلاة المسافرين وقصرها / 435
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 27 كتاب الإيمان: 27 باب تطوع قيام رمضان من الإيمان»
Sayyida Aisha (may Allah be pleased with her) narrated that the Messenger of Allah (peace and blessings be upon him) got up at night and prayed in the mosque, and some companions also stood to pray behind him. In the morning, those companions mentioned this to other people, so (the next day) even more people gathered and prayed behind him. The following morning, the news spread even more, and then, on the third night, a large number of people gathered, and when the Messenger of Allah (peace and blessings be upon him) stood up, those companions started praying behind him. On the fourth night, the mosque was so full of worshippers that there was no room left. But that night, the Noble Prophet (peace and blessings be upon him) did not lead this prayer, and after the Fajr prayer, he addressed the people. First, he recited the testimony of faith, then said: "As for what follows, I am not afraid of your presence here, but I feared that this prayer might be made obligatory upon you, and then you would not be able to perform it."
Hadith Referenceاللؤلؤ والمرجان / كتاب صلاة المسافرين وقصرها / 436
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 11 كتاب الجمعة: 29 باب من قال في الخطبة بعد الثناء أما بعد»