De Somniis (lib. i-ii)

Accordingly, one of the followers of Moses, having compared this speech to a river, has said in the Psalms, "The river of God was filled with water;" [*](Psalm lxv. 10. ) and it is absurd to give such a title to any of the rivers which flow upon the earth. But as it seems the psalmist is here speaking of the divine word, which is full of the streams of wisdom, and which has no part of itself empty or desolate, or rather, as some one has said, which is diffused everywhere over the universe, and is raised up on high, on account of the continued and incessant rapidity of that ever-flowing spring.

There is also another expression in the Psalms, such as this, "The course of the river makes glad the city of God." [*](Psalm xlv. 5. ) What city? For the holy city, which exists at present, in which also the holy temple is established, at a great distance from any sea or river, so that it is clear, that the writer here means, figuratively, to speak of some other city than the visible city of God.