Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Miswar bin Makhramah that I and Ibn Abbas (may Allah be pleased with them) entered upon Hazrat Umar after he had been attacked and was unconscious. So we said, "Nothing will awaken him more than mentioning the prayer." Thus, we said, "O Commander of the Faithful! The prayer!" Upon this, Hazrat Umar became alert and said, "The prayer! There is no share in Islam for the one who abandons the prayer." Then Hazrat Umar performed the prayer in that condition while blood was flowing from his wounds.