It is narrated from Sayyiduna al-Miswar bin Makhramah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Let none of you ever pray while he feels any kind of discomfort," meaning the need to relieve oneself or urinate.
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from al-Zuhri (may Allah have mercy on him) except his nephew, and al-Waqidi (may Allah have mercy on him) is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الألف / 2824
Hadith Gradingمحدثین:تفرد به الواقدي
Hadith Takhrij«قال الطبراني: لم يروه عن الزهري إلا ابن أخيه محمد بن عبد الله تفرد به الواقدي «الإعلام بسنته عليه الصلاة والسلام بشرح سنن ابن ماجه الإمام، ج 3، ص 89»» «أخرجه الطبراني فى «الكبير» برقم: 22»