首楞嚴義疏注經 2.119

2.119

"'Just as a person uses a finger to point at the moon to show someone, that person should look at the moon by means of the finger. If he instead looks at the finger and takes it to be the substance of the moon, this person not only loses the disc of the moon, but also loses his finger. Why? Because he takes the pointing finger to be the bright moon.'"