Sahih Muslim, Hadith 2870a

When the servant is placed in his grave, his companions retrace their steps, and he hears the noise of their footsteps, two angels come to him and make him sit and say to him: What you have to say about this person (the Prophet)? If he is a believer, he would say: I bear testimony to the fact that he is a servant of Allah and His Messenger. Then it would be said to him: Look to your seat in the Hellfire, for Allah has substituted (the seat of yours) with a seat in Paradise. Allah's Messenger (ﷺ) said: He would be shown both the seats. Qatada said: It was mentioned to us that his grave (the grave of a believer) expands to seventy cubits and is full with verdure until the Day when they would be resurrected.