Musnad Ahmad 535:1

Yunus ibn Muhammad narrated to us, Layth—meaning Ibn Sa’d—narrated to us, from Yazid—meaning Ibn Abi Habib—that he heard Abdullah ibn al-Harith al-Zubaydi saying: "I am the first person who heard the Prophet, may Allah bless him and grant him peace, say: 'None of you should urinate while facing the Qibla.' And I am the first person who narrated that to the people."