7343. And all the Egyptians digged round about the river for waters to drink. That this signifies a thorough search for truth which they might apply to falsities, is evident from the signification of "digging," as being thorough search (of which in what follows); and from the signification of "waters about the river," as being truths; that "waters about the river" denote truths is because they were outside the river, and were not made blood (that "waters" denote truths, see n. 739, 790, 2702, 3058, 3424, 4976, 5668); and from the signification of "drinking," as being to apply to falsities. That "to drink" is to apply, see n. 5709; for he who drinks applies to himself; but be it known that the application is made according to the quality and state of him who applies to himself. He who is in the affection of truth applies truths to himself according to the state and quality of his affection; he who is in the affection of falsity, when he applies truths to himself, perverts and falsifies them, as can be seen from the fact that Divine truth flows in with all, but is varied with everyone according to the state and quality of his life; and hence that the infernals turn it into falsities, just as they turn Divine good into evil, heavenly loves into diabolical loves, mercy into hatred and cruelty, conjugial love into adulteries; thus into the contraries, because the quality and state of their life are contrary. Hence it is that by "all the Egyptians dug round about the river" is signified a thorough search for truth which they might apply to falsities.
 That with those who are in falsities and evils truth is turned into falsity, and good into evil, and also the converse, is evident from the common maxim that "to the pure all things are pure, and to the impure all things are impure." This can also be illustrated by things in nature; as by the light which is from the sun, which light is white, but still is varied according to the forms into which it flows, whence are colors, being beautiful in beautiful forms, and unbeautiful in unbeautiful ones. It can also be illustrated by the grafting of young shoots in trees, when the shoot engrafted on the common stock bears its own fruit, whereby the juice of the tree is altered as soon as it flows into the ingrafted shoot, and becomes the juice of the shoot fit to produce its leaves and fruits. So it is with the things that flow in with man.
 That "digging" denotes to search thoroughly is because by water, a fountain, and a well, which are digged, are signified truths, which are not digged, but are searched for; and therefore by the same word in the original tongue, when it is applied to truth, is signified to investigate. But in the prophetical books, instead of truth, either "water," or a "fountain," is mentioned; and instead of investigating, "digging," for such is the nature of prophetic speech, as is evident in Moses, where the "well Beer" is spoken of, concerning which Israel sang this song:
Rise up, O spring, answer ye upon it; the spring which the princes digged, the chiefs of the people digged it through the lawgiver, with their staves (Num. 21:17-18);
here by a "spring" is signified the doctrine of truth Divine, and by "digging," the investigation of it.