telling future, one theory
When you are dreaming, you are in a deeper conscious state (obviously). This allows one to tap into the energies of the universe easier and also open up their own chakras in their bodies. your seventh chakra governs clairvoyance; some say that everyone experiences some degree of clairvoyance during dreaming, but put it off as coincidence, happenstance, deja vu, or might not even remember the event ever occurred (depending on how efficiently the average person remembers their dreams).
For example, my sister dreamt of a doorway jammed with people screaming and burning. The very next day, the story of the night club that burnt down in Rhoad Island was all over the news. The craziest part was that there was only one exit and so many people tried evacuating at the same time they actually got stuck in the doorway, the main reason why so many died in that fire.
so I think telling the future while sleeping is entirely possible, and prob happens a lot more than you would think.