Sahih Bukhari
Sahih Bukhari Volume 001, Book 004, Hadith Number 151.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 04. Ablutions (Wudu')
Narated By 'Abdullah bin 'Umar : Once I went up the roof of our house and saw Allah's Apostle answering the call of nature while sitting over two bricks facing Bait-ul-Maqdis (Jerusalem). (See Hadith No. 147).