From the moment we slip into sleep, our soul moves away from our physical body and goes to join the universal soul

"From the moment we slip into sleep, our soul moves away from our physical body and goes to join the universal soul. During the body’s rest, an entire work of cleansing and purification takes place. On its return, the soul finds the house cleaned and washed, and it can take up its work again. If the soul did not leave the body in this way, we would die from poisoning and asphyxiation, because the work of cleansing could not be done. You will say, ‘But why do we have these toxins and poisons?’ Because life is a combustion. All the physical, emotional and mental activities we know as ‘life’ produce a release of forces, but they also leave behind rubbish which takes a while to be eliminated. So it is necessary for the soul to withdraw from the body so the cleansing can take place. This is how nature has resolved the problem of life."