Seek it (Lailat-ul-Qadr) in the last (ten nights). If one among you shows slackness and weakness (in the earlier part of Ramadan), it should not be allowed to prevail upon him in the last week.
Sahih Muslim Book 13, Hadith 271
← Previous Hadith I heard Allah's Messenger (ﷺ) as saying: So far as Lailat-ul-Qadr is concerned. some persons among you have seen it (in a dream) in the first week and some persons among you have been shown that it is in the last week; so seek it in the last ten (nights).

Sahih Muslim Book 13, Hadith 270 Next Hadith → He who is anxious to seek it (Lailat-ul-Qadr) should seek it in the last ten (nights of Ramadan).

Sahih Muslim Book 13, Hadith 272