Praise be to Allaah.
Ibn al-Qayyim (may Allaah have mercy on him) said:
The soul (al-rooh) is connected to the body in five different ways, to
which different rules apply.
Its connection to the body as a foetus in his mothers womb.
Its connection to the body after a person is born.
Its connection to the body when a person is asleep, when the soul is
connected in one way and separated from it in another way.
Its connection to the body in al-Barzakh (the period between a person's
death and the Day of Resurrection), when it has departed from the body and separated from
it, but is not separated completely in such a way that there is no connection at all. We
have mentioned at the beginning of this reply that there are ahaadeeth and reports which
indicate that the soul is returned to the body when somebody sends the greeting of salaam
to a deceased person. This returning is of a special nature which does not mean that the
life is restored to the body before the Day of Resurrection.
Its connection to the body on the Day when bodies will be resurrected.
This is the most perfect type of connection to the body, and has no comparison to the
previous types, because after that the body will never die, sleep or have anything wrong
When a person is asleep, his soul is in his body and he is alive,
although his being alive is not the same as that of a person who is awake, for sleep is
comparable to death. Similarly, when a dead person's soul is returned to his body (when
the greeting is sent upon him), he is in a state between one who is alive and one who is
dead, whose soul is not restored to his body. This is like the case of a sleeping person
who is in a state between life and death. We hope that this will dispel a lot of your
Kitaab al-Rooh, 44.