6346. 'Light as water' means that faith alone does not possess such qualities, neither glory nor powerfulness. This is clear from the meaning of 'being light as water' as having no weight or worth. The fact that faith alone is meant, that is, faith separated from charity, is evident from the things mentioned in what follows that involve Reuben, and that involve Simeon and Levi. Those men - Reuben, Simeon, and Levi - are used here also to refer to faith alone or faith separated from charity.

'The bite of a snake' or 'serpent,' as in Amos 5:19, this signifies falsification of the Word from the interior dominion of falsity from evil.

(références: Apocalypse Explained 781)