Maliks Muwatta Book 2, Hadith Number 53.

Section : What to Do in the Event of Bleeding from a Wound or a Nose-Bleed.

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 Khattab on the night he was stabbed and had woken him up for the subh prayer and Umar had said, ”Yes. Whoever stops doing the prayer will get nothing from Islam,” and he did the prayer with blood pouring from his wound.