"And Jacob was left alone"
Rabbi Chiya leads a discussion on the evil spirits that gain influence as a result of the diminution of the moon. These spirits assail people when they are sleeping - since this is a time when the soul leaves the body - and cause people to defile themselves. Thus, we learn, it is incumbent on man to purify himself and follow the paths of the Torah.
The rabbis also warn us not to travel a lonely road by ourselves or to go out at night when there are no people about, especially without the light of the moon. At these times, evil spirits - those with whom Bilaam was associated - are at large.
Discord and turmoil in our lives can be traced to negative influences and evil forces that dwell in our midst. Our negative behavior creates openings for destructive entities, but the Light of this passage seals these openings shut. Moreover, the spiritual energy purifies our soul, raises our consciousness, and inspires us to eliminate self-destructive impulses that create the cracks and crevices through which dark forces enter our lives.