9052. Tooth for tooth. That this signifies if anything in the exterior intellectual, is evident from the signification of "a tooth," as being the exterior intellectual, and therefore natural truth, for this makes the life of this understanding. That "the teeth" have this signification is because they grind like a mill, and thus prepare, the food which is to nourish the body; here the food which is to nourish the soul. The food which nourishes the soul is intelligence and wisdom. This is first received, ground, and prepared by means of the knowledges of truth and good in the natural. (That it is intelligence and wisdom which is called "spiritual and celestial food," see n. 56-58, 680, 1480, 4792, 5147, 5293, 5340, 5342, 5576, 5579, 5915, 8562, 9003.) From this it is plain whence it is that "the teeth" signify the exterior understanding. What the exterior understanding is can be seen from what was shown just above (n. 9051) concerning the interior understanding.
 That "the teeth" signify natural truth, which belongs to the exterior understanding, and in the opposite sense the falsity which destroys this truth, is evident from the following passages in the Word. That they signify natural truth, in Moses:
His eyes shall be redder than wine, and his teeth whiter than milk (Gen. 49:12).
Here also both "eyes" and "teeth" are mentioned together. The subject treated of is Judah, by whom is meant the Lord as to the Divine celestial (n. 6363); "the eyes" signify the Divine intellectual of the Lord (n. 6379); and "the teeth," His Divine natural (n. 6380), thus also the Divine truth in the natural.
 In Amos:
I have given you emptiness of teeth in all your cities, and lack of bread in all your places (Amos. 4:6).
"Emptiness of teeth" denotes scarcity of truth; and "lack of bread," scarcity of good. From all this it is evident what is meant by the "gnashing of teeth" among those who are in hell (Matt. 8:12; 13:42, 50; 22:13; 25:30; Luke 13:28), namely, the collision of falsities with the truths of faith. For as before said, "the teeth," in the opposite sense, signify the falsity which destroys truth; as in David:
Arise, O Jehovah; save me, O my God; for Thou wilt smite all mine enemies on the jaw; Thou wilt break the teeth of the wicked (Ps. 3:7).
"To break the teeth of the wicked" denotes to break the falsities by which they destroy truths. In the same:
As to my soul I lie in the midst of lions, their teeth are spears and arrows, and their tongue a sharp sword (Ps. 57:4).
"The teeth of lions" denote the falsities that destroy truths; "lions," falsities from evil in their power (n. 6367, 6369).
 In the same:
Destroy their teeth, O God, in their mouth; turn aside the grinders of the young lions (Ps. 58:6).
A nation is come up upon My land, strong, and without number; his teeth are the teeth of a lion, and he hath the grinders of a great lion. He hath reduced My vine to a waste; and My fig-tree into froth (Joel 1:6, 7).
"Teeth" and "grinders" denote the falsities that destroy the truths of the church; a "vine" denotes the spiritual church (n. 1069, 5113, 6376); and a "fig-tree" its natural good (n. 217, 4231, 5113). That "teeth" have this signification is plain also from the fact that they are attributed to a nation which will lay waste. In John:
The shapes of the locusts were like unto horses prepared for war; they had hair as the hair of women, and their teeth were as the teeth of lions (John 9:7, 8).
"Locusts" denote those who are in external falsities (n. 7643), from which it is also evident that "teeth" denote falsities that destroy truths.