Asma’ daughter of Abu Bakr said, “God’s messenger arose to deliver an address in which he mentioned the trial a man will endure in the grave. On his mentioning that, the Muslims gave a shout of dismay."
Bukhari transmitted it thus, but Nasa’i added, “which prevented me from grasping what God's messenger had said. So when the clamour died down I said to a man near me, ‘God bless you, what did God’s messenger say at the end of his address?' He replied that he said he had had a revelation that the trial they would endure in their graves would approximate to that of ad-Dajjal."
Ibn ‘Umar reported God’s messenger as saying, “This is the one1 on account of whom the throne moved, for whom the gates of heaven were opened, and whose funeral seventy thousand angels attended. He was compressed, but afterwards the pressure was removed from him."
Jabir reported the Prophet as saying, “When a dead man is covered up in his grave he will be shown the setting sun and will sit up, rub his eyes, and say, ‘Let me observe the prayer’."
We went out with God’s messenger to Sa'd b. Mu'adh when he died. God’s messenger prayed over him, and when he was placed in his grave and the ground was levelled over him, God’s messenger extolled God and we did so also at great length. He then said, “God is most great," and we did the same. Someone asked him why he had extolled God and then said, “God is most great," to which he replied, “This upright servant’s grave had closed in on him, but finally God removed the pressure from him."