(40) باب فَضْلِ لَيْلَةِ الْقَدْرِ وَالْحَثِّ عَلَى طَلَبِهَا وَبَيَانِ مَحَلِّهَا وَأَرْجَى أَوْقَاتِ طَلَبِهَا
Ibn 'Umar (Allah be pleased with them) reported that some persons among the Companions of the Messenger of Allah (ﷺ) were shown Lailat- ul-Qadr while sleeping in the last week (of Ramadan). Thereupon Allah's Messenger (ﷺ) said:
I see that your dreams agree regarding the last week; so he who wants to seek it should seek it in the last week (during the night).
Reference: Sahih Muslim 1165 a
In-book reference: Book 13, Hadith 267
USC-MSA web (English) reference(deprecated numbering scheme): Book 6, Hadith 2617