Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Asma that the Holy Prophet, peace and blessings be upon him, said: Revelation has been sent to me that surely you will be tested in your graves (you will be subjected to a trial), similar to or near the trial of the Antichrist (Dajjal). Then one of you will be brought and it will be said to him, "What do you know about this man?" The Prophet said, the believer will say, "He is Muhammad, peace be upon him, the Messenger of Allah, who came to us with clear proofs and guidance. We accepted him and followed him." It will be said to him, "Sleep in peace and safety; we knew that you were a believer in Allah." However, the hypocrite and the doubter will say, "I do not know who he is." Hazrat Asma says, he will say, "I do not know; I heard people saying something, so I said the same."