Musannaf Ibn Abi Shaybah

Hazrat Abu Bakr bin Abi Musa narrates that Hazrat Abu Musa came to Hazrat Umar bin Khattab after the Isha prayer. Hazrat Umar bin Khattab asked him, "Why have you come?" He replied, "I have come to discuss some matters with you." Hazrat Umar said, "At this hour?" Hazrat Abu Musa said, "It is a matter of religion." Upon this, Hazrat Umar sat with him, and both of them talked the whole night. Then Hazrat Abu Musa said, "O Commander of the Faithful! The time for prayer has come." Upon this, Hazrat Umar said, "We were already in prayer."