In Revelations, when the sun and moon fail to give their light, it far more likely to mean that
prayer and meditation cease to provide a link to God anymore, rather than that the actual sun and moon are darkened.
From these he put together a theory of contemplative
prayer: That as person becomes increasingly contemplative in his
prayer, he will move from «
meditation» (thinking about or imagining Our Lord, for example) to a place where
meditation, affections,
and thinking
ceases and are replaced by what seems to be an experience of nothing, but is closer union with God.