10074. And the two kidneys, and the fat that is upon them. That this signifies the interior truth of the natural man purified, and its good, is evident from the signification of “the kidneys,” as being the interior truth of the external or natural man; and from the signification of “the fat that is upon them,” as being the good of this (see n. 10032). That it is truth purified which is signified by “the kidneys,” is because the kidneys are organs which purify the blood (n. 10032); and the “blood” denotes truth (n. 9393, 10026).

10032. And the two kidneys, and the fat that is upon them. That this signifies the interior truth of the external or natural man, and its good, is evident from the signification of “the kidneys,” as being interior truths (of which below); and from the signification of “fat,” as being good (of which above, n. 10029); that it denotes the good of this truth is because it was the fat upon the kidneys. It is said “the good of this truth,” because every good has its own truth, and every truth its own good. There are innumerable kinds of good, and every kind of good has a truth which is of the same kind; for in the universal heaven there are goods and truths which make the life there, and they are everywhere various. The quality of the good which is signified by “the fat upon the kidneys,” is evident from the truths which are signified by “the kidneys.” By “the kidneys” are signified truths which explore, purify, and correct, taking this signification from their function. This shows what is signified by “kidneys,” or “reins,” in the following passages, in Jeremiah:

Jehovah trieth the reins and the heart (Jeremiah 11:20).

Thou that triest the hearts and the reins, O just God (Psalms 7:9).

O Jehovah, explore my reins and my heart (Psalms 26:2).

O Jehovah, Thou possessest my reins (Psalms 139:13).

I am He who searcheth the reins and the heart (Revelation 2:23).

“To search,” and “to try, the kidneys,” or “reins,” denotes to explore the truths of faith; and “to search,” and “try, the heart” denotes to explore the goods of love, for “the heart” denotes the good of love (n. 3883-3896, 7542, 9050). That the truths of faith are signified by “the kidneys” is very evident in David:

O Jehovah, Thou desirest truth in the reins (Psalms 51:6).

That by “the kidneys” is signified interior truth and its exploration, is because by the ureters and the bladder, which go forth from the kidneys, is signified exterior truth and its exploration, as also its correction (n. 5381-5384).