‘Umar b. al-Khattab’s Words on Salah
`Umar (may Allah be pleased with him) became unconscious after he was stabbed, and according to Al Miswar bin Makhramah, it was said: “Nothing would wake him up except the call to prayer, if he is still alive.”
They said to him, “The prayer has finished, O Chief of the Faithful!”
He woke up and said, “The prayer, by Allah! Verily, there is no share in Islam for whoever abandons the prayer.”
He performed the prayer while his wound was bleeding.
Source: Sifat as Safwah 2/131