Muwatta Malik, Book 19, Hadith 705 (In-Book) ⓘ

Ziyad related to me from Malik from Nafi from Ibn 'Umar that some of the companions of the Messenger of Allah, may Allah bless him and grant him peace, were shown Laylat al-Qadr in their sleep during the last seven days. The Messenger of Allah, may Allah bless him and grant him peace, said, "I see that your visions agree about the last seven days, so whoever is searching for it should do so in the last seven days."

وَحَدَّثَنِي زِيَادٌ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رِجَالاً، مِنْ أَصْحَابِ رَسُولِ اللَّهِ صلى الله عليه وسلم أُرُوا لَيْلَةَ الْقَدْرِ فِي الْمَنَامِ فِي السَّبْعِ الأَوَاخِرِ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ إِنِّي أَرَى رُؤْيَاكُمْ قَدْ تَوَاطَأَتْ فِي السَّبْعِ الأَوَاخِرِ فَمَنْ كَانَ مُتَحَرِّيَهَا فَلْيَتَحَرَّهَا فِي السَّبْعِ الأَوَاخِرِ ‏" ‏ ‏.‏