Hadith 4:190
Ibn ‘Uyaynah narrated to us, from Zayd ibn Aslam, from his brother, from his father: ‘Umar broke his fast during the month of Ramadan, and it was said to him, "The sun has risen [i.e., it is still day]." He said, "It is a minor matter; we have been striving."
حدثنا بن عيينة عن زيد بن اسلم عن اخيه عن أبيه افطر عمر في شهر رمضان فقيل له قد طلعت الشمس فقال خطب يسير قد كنا جاهدين