It is narrated from Sayyiduna Abu Mahdhurah (may Allah be pleased with him): When Sayyiduna Umar (may Allah be pleased with him) came to Makkah, I gave the adhan, and Umar (may Allah be pleased with him) said to me: O Abu Mahdhurah, did you not fear that your belly (the part below the navel) would burst from straining?
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1862