5497. And behold it was in the mouth of his bag. That this signifies that they were bestowed and stored up in the threshold of the exterior natural, is evident from the signification of the "mouth of the bag," as being the threshold of the exterior natural. That they were stored up there is implied, and that they were bestowed follows from what is said before-that it was without any ability of their own. As the mouth was the fore part of the sack, therefore nothing else is signified by it than the fore part of the receptacle, thus the exterior natural, for this also is before (that a "sack" denotes a receptacle may be seen, n. 5289, 5494). In order that it may be known what the exterior and the interior natural are, it shall be again briefly explained. A boy, being not yet of mature age, cannot think from anything higher than the exterior natural; for he composes his ideas from things of sense. But as he grows up, and from things of sense draws conclusions as to causes, he thereby begins to think from the interior natural; for from things of sense he then forms some truths, which rise above the senses, but still remain within the things that are in nature. But when he becomes a young man, if as he then matures he cultivates his rational, he thus forms reasons from the things in the interior natural, which reasons are truths still higher, and are as it were drawn out from the things in the interior natural. The ideas of thought from these are called in the learned world intellectual and immaterial ideas; while the ideas from the memory-knowledges in both naturals, insofar as from the senses they partake of the world, are called material ideas. In this way man mounts in his understanding from the world toward heaven. But still he does not come into heaven with his understanding unless he receives good from the Lord, which is continually present and flowing in; and if he receives good, truths also are bestowed on him, for in good all truths find their abode; and according as truths are bestowed on him, so also is understanding, by reason of which he is in heaven.