Sunan Abi Dawud 12
سنن أبي داود#12SahihNarrated 'Abd Allaah b. 'Umar :I ascended the roof of the house and saw the Apostle of Allaah ( sal Allaahu alayhi wa sallam) sitting on two bricks facing Jerusalem (Bait al-Maqdis) for relieving himself
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (145) Sahih Muslim (266)
In-book reference: 1:12