Is the Prophet Alive in His Grave?

Question :

Regarding the life of the Prophet, was the Prophet alive in his noble grave through the return of his soul to his body, as in the physical life of this world, or alive in the highest heaven, living the life of the Hereafter in Al- Barzakh, without discomfort, as the Prophet said, when death approached him:
O Allah, with the Highest Companion.»

And is his enlightened body now as it was when it was placed in his grave, without a soul, while his soul is in the highest heaven? And is the joining of the soul and the body waiting upon the Day of Resurrection, when, as Allah, the Most High says:
And when the souls shall be joined (with their bodies)

Answer:

Our Prophet, Muhammad is alive in his grave, living the life of Al-Barzakh, where he is enjoying the ease and comfort which Allah has prepared for him, as a fitting reward for that which he earned in the life of this world. But his soul has not returned to him, that he may live as he did in this world, nor does it connect with him in the grave, so that he lives as he will on the Day of Resurrection. Rather, it is the life of Al-Barzakh, which is something between the life he lived in this world and the life of the Hereafter. Based upon this, it is clear that he died, just as the Prophets before him and others died, apart from 'Isa, upon him be peace, who will descend at the end of time, after which he will die. Allah, the Most High says:
And We granted not to any human being immortality before you (O Muhammad). Then if you die, would they live forever?

And He says:
Whatsoever is on it (the earth) will perish. And the Face of your Lord, full of Majesty and Honor will abide forever.

And He says:
Verily, you (O Muhammad will die and verily they (too) will die.

- and other such examples among the Verses which prove that Allah brought death to him. And because the Companions washed him and prayed over him and buried him. Had he been alive, as in the life of this world, they would not have treated him as they treated others who died.

Fatimah, may Allah be pleased with her, requested her inheritance from her father, because she believed him to be dead, and none of the Companions contradicted her in this belief. Abu Bakr, may Allah be pleased with him, answered her, saying that the Prophets are not inherited from. The Companions agreed upon the choice of the caliph of the Muslims who would succeed him, which resulted in the choosing of Abu Bakr, may Allah be pleased with him, as caliph. Had he been alive, as he was in the life of this world, they would not have done so. There was, therefore consensus among them as to his death. When the trials and problems proliferated during the rule of 'Uthman and 'Ali, may Allah be pleased with them both, before and after this, they did not go to his grave in order to ask for his advice, or for a way out of these trials and problems, or the path to follow in order to find a solution to them. If he had been alive, as he was in the life of this world, they would not have neglected to do this, when they were in need of one who could lead them out of the trials which they experienced.

Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 1 Pages 283-284-285