A lesson in a dream stands for something life is trying to teach you. Tradition reads its subject, and whether you follow it, as a hint about what you are learning right now.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.