Yahya related to me from Hisham ibn Urwa from his father that al-Miswar ibn Makhrama told him that he had visited Umar ibn al Khattabon the night he was stabbed and had woken him up for the subh prayerand Umar had said, ''Yes. Whoever stops doing the prayer will getnothing from Islam," and he did the prayer with blood pouring from hiswound.
USC-MSA web (English) reference: Book 2, Hadith 53
Arabic reference: Book 2, Hadith 83