Maliks Muwatta Book 21, Hadith Number 30.
Section : The Martyrs in the Way of Allah.
Yahya related to me from Malik from Zayd ibn Aslam that Umar ibn al-Khattab used to say, “O Allah! Do not let me be slain by the hand of a man who has prayed a single prostration to You with which he will dispute with me before You on the Day of Rising!”