Sahih Bukhari
Sahih Bukhari Volume 001, Book 008, Hadith Number 424.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 08. Prayers (Salat)
Narated By Ibn 'Umar : The Prophet had said, "Offer some of your prayers (Nawafil) at home, and do not take your houses as graves."