In Exodus 12:19, this signifies one who is born in the church. (Arcana Coelestia 7908)

In Leviticus 23:42, this signifies people in the good of charity. (Arcana Coelestia 9296[6])

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.