I went up to the roof of the house of my sister Hafsa and saw the Messenger of Allah (ﷺ) relieving himself facing Syria. with his back to the Qibla.
Sahih Muslim Book 2, Hadith 79
← Previous Hadith I was offering my prayer in the mosque and Abdullah b. Umar was sitting there reclining with his back towards the Qibla. After completing my prayer. I went to him from one side. Abdullah said: People say when you go to the latrine, you should neither turn your face towards the Qibla nor towards Bait-ul-Maqdis. 'Abdullah said (farther): I went up to the roof of the house and saw the Messenger of Allah (ﷺ) squatting on two bricks for relieving himself with his face towards Bait-al-Maqdis.

Sahih Muslim Book 2, Hadith 78 Next Hadith → The Messenger of Allah (ﷺ) said: None of you should hold penis with his right hand while urinating, or wipe himself with his right hand in privy and should not breathe into the vessel (from which he drinks).

Sahih Muslim Book 2, Hadith 80