The whole essence of Zen consists in walking along the razor’s edge of Now—to be so utterly, so completely present that no problem, no suffering, nothing that is not who you are in your essence, can survive in you. In the Now, in the absence of time, all your problems dissolve. Suffering needs time; it cannot survive in the Now.
The great Zen Master Rinzai, in order to take his students’ attention away from time, would often raise his finger and slowly ask: “What, at this moment, is lacking?” A powerful question that does not require an answer on the level of the mind. It is designed to take your attention deeply into the Now. A similar question in the Zen tradition is this: “If not now, when?”
—Eckhart Tolle, The Power of Now