He who is ruled by spiritual intelligence, without being asleep, puts his senses to sleep, so that unseen things may emerge from the world of the Soul.
Even in his waking state he dreams dreams (visions) and opens withal the gates of Heaven.
The Prophet said of this world, which is substantial in appearance, that it is the sleeper’s dream.
You have accepted this statement conventionally, but the travellers on the mystic Way have beheld this truth clairvoyantly, without relation from the Prophet.
You are asleep in the daytime: do not say that this is not sleep. The shadow is derivative, the origin of it is naught but the moonlight.
Know, O comrade, that your sleep and waking is as though a sleeper should dream that he has gone to sleep.
He thinks, “Now I am asleep”, and is unaware that he is really in the second sleep.
From Rumi’s Mathnawi Book 3