Sahih Bukhari
Sahih Bukhari Volume 003, Book 033, Hadith Number 242.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 33. Retiring To a Masjid for Remembrance Of Allah (I'tikaf)
Narated By Abdullah bin Umar : Allah's Apostle used to practise Itikaf in the last ten days of the month of Ramadan.