Think the unthinkable. You must think the unthinkable means think not about something. Usually when you think, you think about something. But if your thinking mind is directed the opposite way, that is to think the unthinkable. Your mind is still clear, but there is no object.
One-stroke brushplay by Kazuaki Tanahashi
—cuke.com/ig for links to the source of the image. Excerpt from Shunryu Suzuki lecture 67-12-04-A as found on shunryusuzuki.com, edited by PF. Go to instagram.com/cuke_archives for the Instagram version.