9051. Eye for eye. That this signifies if they shall injure anything in the interior intellectual, is evident from the signification of "the eye," as being the understanding, here the interior understanding, the life of which is the life of faith. Man has an exterior understanding, and an interior understanding. The exterior understanding is where the thought is that comes to perception; but the interior understanding is where the thought is that does not come to perception; nevertheless it does come to the perception of angels. This latter understanding is that which is enlightened by the Lord when man receives faith, for it is in the light of heaven, and in it is the spiritual life of man, which is not so manifest to him in the world, but is manifest in the other life, when the man becomes an angel among the angels in heaven. Meanwhile this life lies hidden within the thought of the exterior understanding, and produces therein a holy and reverent feeling for the Lord, for love and faith in Him, for the Word, and for all other things of the church. The reason why "the eye" denotes the understanding, is that the eye corresponds to the understanding, for the understanding sees by virtue of the light of heaven, but the eye by virtue of the light of the world. Those things which the former eye or understanding sees are spiritual, and the field of its view is the memory-knowledge in man's memory. But the things which the external eye sees are earthly, and the field of its view is everything that appears in the world. That in the spiritual sense "the eye" denotes the understanding, and also faith, is because faith makes the life of the interior understanding (see n. 2701, 4403-4421, 4523-4534).
 He who does not know that the understanding is meant in the Word by "the eye," cannot know what is signified by what the Lord spoke concerning the eye in the Evangelists, as by these words:
If thy right eye causeth thee to stumble, pluck it out; it is good for thee to enter into the kingdom of God with one eye, rather than having two eyes to be cast into the Gehenna of fire (Mark 9:47; Matt. 5:29).
Everyone knows that the eye is not to be plucked out, though it cause one to stumble, and that no one enters into the kingdom of God with one eye; but by "the right eye" is signified falsity of faith concerning the Lord, and this is what is to be plucked out. Again:
The light of the body is the eye; if therefore thine eye be simple, thy whole body shall be full of light. But if thine eye be evil, thy whole body shall be darkened. If therefore the light that is in thee be darkness, how great is the darkness (Matt. 6:22, 23; Luke 11:34).
Neither in this passage is the eye meant by "eye," but the understanding of the truth of faith. Hence the eye is called "the light of the body," and it is said, "if the light that is in thee be darkness, how great is the darkness," for in the spiritual sense "darkness" denotes falsities of faith (n. 1839, 1860, 4418, 4531, 7688, 7711).
 And again:
Why beholdest thou the mote that is in thy brother's eye, but understandest not the beam that is in thine own eye? (Matt. 7:3-5).
"To behold a mote in the eye of a brother" denotes something erroneous in respect to the understanding of truth; and "the beam in one's own eye" denotes the huge evil of falsity; for in the internal sense "wood" denotes good, and in the opposite sense evil (n. 643, 2784, 2812, 3720, 8354). Moreover in the other life good is represented by a beam; and therefore those who feign good in themselves seem to carry a beam, and thus go safely. Without this signification of "the eye," and of "a beam," what could be meant by "seeing a beam in the eye?" If it is not known that in the Word "the eye" denotes the understanding of truth, which is faith, neither can it be known what is involved in what the Lord did when He healed a blind man, that is, when "He spat on the ground and made clay of the spittle, and said unto him, Wash thee in the pool of Siloam" (John 9:6, 7). As the Lord's miracles, like all Divine miracles, involved those things which are of the Lord's kingdom and church (n. 7337, 8364), so also does this.