It is Mushin No Shin, the mind of no mind, no intention, no expectations.
"Mushin is achieved when a person's mind is free from thoughts of anger, fear or ego during combat or everyday life. There is an absence of discursive thought and judgment, so the person is totally free to act and react towards an opponent without hesitation and without disturbance from such thoughts. At this point, a person relies not on what they think should be the next move, but what is their trained natural reaction or what is felt intuitively.
It is not a state of relaxed, near-sleepfulness, however. The mind could be said to be working at a very high speed, but with no intentions, plans or direction. In analogy a clear mind is compared to a still pond, which is able to clearly reflect the moon and trees. But just as waves in the pond will distort the picture of reality, so will the thoughts we hold onto disrupt the true perception of reality."