Finger pointing at the moon - This is a very important Zen Koan about the role of Dhamma (pointing finger) and ultimate goal, Nirvana (the Moon). Dhamma's role is to point the finger at the direction of Nirvana as a guidance. The goal is to look at the Moon and not to get stuck in admiring the finger which is pointing at the Moon!
This Koan can be compared to the Raft metaphor in Theravada Buddhism. There, Dhamma is often compared as a raft to cross the river (Samsara) - achieving Nirvana (or Nibbana, in Pali). One would be foolish to carry with himself the raft once they cross the river.
Thich Nhat Hanh's quote on the same subject - Quote by Thich Nhat Hanh: “Bhikkhus, the teaching is merely a vehicle to describe the truth”