The Book of Fasting (Kitab Al-Sawm)

Muslim :: Book 6 : Hadith 2621

Ibn Umar (Allah be pleased with them) reported Allah's Messenger (may peace be upon him) as saying: 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.

Source materials are from the University of Southern California MSA site
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