Close your eyes and say to yourself: “I wonder what my next thought is going to be.” Then become very alert… — Eckhart Tolle

Close your eyes and say to yourself: “I wonder what my next thought is going to be.” Then become very alert and wait for the next thought. Be like a cat watching a mouse hole. What thought is going to come out of the mouse hole?

Source: Wikiquote · CC BY-SA 4.0