TABARANI 13996:
from Bilāl b. ʿAbdullāh b. Unays from his father —
[Machine] He said, "O Messenger of Allah, inform me about the night in which Laylat al-Qadr (the Night of Decree) is sought." He said, "If people do not offer prayer except on that night, I would have informed you. But seek it in the last ten nights of the month."
الطبراني ١٣٩٩٦:
عن بلال بن عبد الله بن انيس عن أبيه —
أَنَّهُ قَالَ يَا رَسُولَ اللهِ أَخْبِرْنِي بِلَيْلَةٍ يُبْتَغَى فِيهَا لَيْلَةُ الْقَدْرِ فَقَالَ «لَوْلَا أَنْ يَنْزِلَ النَّاسُ الصَّلَاةَ إِلَّا تِلْكَ اللَّيْلَةَ لَأَخْبَرْتُكَ وَلَكِنِ ابْتَغِهَا فِي ثَلَاثٍ وَعِشْرِينَ مِنَ الشَّهْرِ»
hadithunlocked.com