Musannaf Ibn Abi Shaybah

Hazrat Abdur Rahman bin Auf narrates that I presented myself before the Holy Prophet (peace and blessings be upon him); he was in prostration. When he raised his head from prostration, I submitted, "O Messenger of Allah! You prolonged the prostration!" He replied, "I performed this prostration because Allah Almighty has bestowed a favor upon me regarding my Ummah."