One day I climbed up onto the roof of Hafsah's house and saw the Messenger of Allah ﷺ relieving himself, facing Sham with his back to the qiblah.
حدثنا عبدة حدثنا عبيد الله عن محمد بن يحيى بن حبان عن عمه واسع
رقيت يوما فوق بيت حفصة فرأيت رسول الله ﷺ على حاجته مستقبل الشام مستدبر القبلة
Its isnad is sahih. Ubaydullah is Ibn Umar bin Hafs. Wasi is Ibn Hibban, with a fatha on the ha and a doubled ba, Ibn Munqidh bin Amr, and he is a trustworthy taabi, and Bukhari mentioned him in al-Kabir, 4/2/190.The hadith was narrated by Tirmidhi, 1:22, from Hannad, from Abdah, with this isnad, and he said, a hasan sahih hadith. It was also narrated by the group, as in al-Muntaqa, 131.