Musnad Ahmad 535:2

Ad-Dahhak ibn Makhlad narrated to us, from Abd al-Hamid—meaning Ibn Ja'far—who said: Yazid ibn Abi Habib narrated to me, from Abdullah ibn al-Harith ibn Juz' az-Zubaydi, who said: "I am the first of the Muslims to hear the Prophet, may Allah bless him and grant him peace, forbidding anyone from urinating while facing the Qibla." So I went out to the people and informed them.