Your mind follows your breathing. While you are following the breath, drop the notion of “I am breathing.” No mind, no body—simply be aware of the moment of breathing. Drop the ideas of time and space, body and mind, and just “be” sitting.
Refrain from trying to stop your thinking—let it stop by itself. When a thought comes into your mind, let it come in and let it go out. Your mind will begin to calm down. Nothing comes from outside of mind. The mind includes everything; this is the true understanding of the mind.