'The valley of Siddim was pits after pits of bitumen' means the uncleanness of falsities and evil desires 'And the king of Sodom and {the king] of Gomorrah fled, and they fell there' means that those evils and falsities were overcome 'And the rest fled to the mountain' means that it did not happen to all of them, 'a mountain' meaning self-love and love of the world.