Mental activity in the daytime creates a latent form of habitual thought which again transforms itself at night into various delusory visions sensed by the semi-consciousness. This is called the deceptive and magic-like Bardo of Dream.
MilarepaWhen you run after your thoughts, you are like a dog chasing a stick: every time a stick is thrown, you run after it. Instead, be like a lion who, rather than chasing after the stick, turns to face the thrower. One only throws a stick at a lion once.
Milarepa