What is an instant? In the scriptures, it is said to first place sixty very thin flower petals in a pile; if an archer then shoots the petals with an arrow that has a sharp, fine needle inserted on the arrowhead, the needle tip will pass through the sixty petals in a flash. Relying just on our eye, we will think the needle tip pierces all sixty petals at the same time; actually the needle tip passes through the petals in an orderly way, that is, gradually a step at a time. When it passes through one petal, it is called an instant.

- Quote from The Four Seals of Dhama, "The Practice of Realizing Emptiness"