Arcana Coelestia#8287
8287. 'The floods stood as a heap' means that those constantly attempting what was evil could not engage in any molestation whatever. This is clear from the meaning of 'standing as a heap', when it refers to falsities arising from evil, as constantly attempting what is evil, for when floods stand as a heap they are overhanging and endeavouring to rush down, but are held back by a stronger force; and from the meaning of 'the floods', like 'the waters', as falsities arising from evil, 7307, 8137, 8138. But they are called 'the floods' on account of their attempt to flow in, that is, to molest.
Arcana Coelestia#8138
8138. 'In Pharaoh and in all his army' means the submersion into hell of those steeped in falsities arising from evil, and their encompassment there by falsities as if by waters. This is clear from what has been mentioned immediately above in 8137, that 'Pharaoh' means those who were cast into hell, as also does 'his army', 'Pharaoh' being those steeped in falsities arising from evil, and 'his army' the falsities themselves. 'Armies' are truths springing from good, see 3448, 7236, 7988, and therefore in the contrary sense they are falsities arising from evil, 3448. The expression 'encompassment by falsities as if by waters' is used because falsities that arise from evil - the kind of falsities that exist with those belonging to the Church who have championed separated faith and have led a life of evil - are seen there as waters, 8137. This also is why deluges of water mean situations in which truth is laid waste while the water present in them means falsities, 705, 739, 756, 6346, 6853.