Arcana Coelestia #7881
7881. 'And that day shall be to you for a memorial' means the essential nature of that state in worship. This is clear from the meaning of 'day' as state, dealt with in 23, 487, 488, 493, 2788, 3462, 3785, 4850, 5672, 5962, 6110; and from the meaning of 'memorial' as essential nature in worship, dealt with in 6888.
Arcana Coelestia #2847
2847. 'I will certainly multiply' means derivations of truth from this affection. This is clear from the use of 'being multiplied' as having reference to truth, here therefore as derivations of truth from that affection, as stated immediately above. As regards 'being fruitful' having reference to good and 'being multiplied' to truth, see 43, 55, 913, 983.