كتاب الاعتكاف
19  
I'tikaf in Ramadan

Ziyad related to me from Malik that he had heard that Said ibn al-Musayyab used to say, "Whoever is present at isha on Laylat al-Qadr has taken his portion from it."

وَحَدَّثَنِي زِيَادٌ، عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ سَعِيدَ بْنَ الْمُسَيَّبِ، كَانَ يَقُولُ مَنْ شَهِدَ الْعِشَاءَ مِنْ لَيْلَةِ الْقَدْرِ فَقَدْ أَخَذَ بِحَظِّهِ مِنْهَا ‏.‏
USC-MSA web (English) reference : Book 19, Hadith 17
Arabic reference : Book 19, Hadith 707