Arcana Coelestia #1020
1020. That these things are meant becomes clear from the fact that everything put together as history from Genesis 1 down to Eber in Chapter 11 means something different from what appears in the letter, and from the consideration that the historical narratives there are purely made-up history customary among the most ancient people. When attesting the truth of some matter they would say that 'Jehovah said it'. Here however 'God' is used because the subject is the spiritual Church. And they did the same when anything true was being, or had been, put into effect.
Arcana Coelestia #8400
8400. 'On the fifteenth day of the second month' means this state considered in relation ... This is clear from the meaning of the number 'fifteen', from the meaning of 'day', and from the meaning of 'month'. 'Month' means the end of the previous state and the beginning of the next, thus a new state, 3814; 'day' means a state in general, 23, 487, 488, 493, 893, 2788, 3462, 3785, 4850, 7680, and 'the fifteenth' means that which is new. For 'fourteen days' or two weeks mean a whole period or state from the beginning to the end of it, 728, 2044, 3845; 'fifteen' therefore means something new, in this instance newness of life, meant by the manna which they received from heaven, 'manna' being the good of truth, which is the life of a spiritual person. Fifteen is similar in meaning to eight, because the eighth day is the first day of a following week. For the meaning of 'the eighth day' as any beginning whatever, thus something new that is distinct and separate from what has gone before, see 2044, 2866; and for the fact that all numbers in the Word have spiritual realities as their meaning, 482, 487, 575, 647, 648, 755, 813, 1963, 1988, 2075, 2252, 3252, 4264, 4495, 4670, 5265, 6175.