Four sources of dreams
I.
Thinking in the day carried
forward even after one has cut off the awareness of one's surroundings.
II.
Thoughts that arise through
imbalance of elements in the body e.g. discomfort and illness. These strong
sensations stir up thoughts.
III.
Spirits or deceased relatives
trying to make contact.
IV.
Clairvoyance.
Dreams are often uncontrollable as they occur after normal awareness is cut
off. How they arise is affected by our own basic nature and habits.
One who is used to having evil thoughts in the day will carry them
forward into his dreams.
Similarly one with good thoughts will have good dreams.