Musannaf Ibn Abi Shayba 3:5557

Zayd ibn al-Hubab narrated to us, from Mu'awiyah ibn Salih, he said: Safar ibn Nusayr al-Asadi narrated to me, from Yazid ibn Shurayh al-Hadrami, that he heard Abu Umamah saying: The Messenger of Allah (may Allah bless him and grant him peace) said: "None of you should come to the prayer while he is suppressing the urge to urinate, until he relieves himself."