There are several references to wind, sunshine, darkness, and moonlight in this story. As the story opens, the bishop is sitting in the daylight on the ship, and the weather is described as "fair" or sunny. However, we told twice that the bishop cannot see:
He could see nothing however, but the sea glistening in the sunshine.
The Bishop looked carefully, but his unaccustomed eyes could make out nothing but the water shimmering in the sun.
These images symbolize the bishop's spiritual blindness.
Wind is referred to twice as a natural phenomenon: we learn as the story opens that the wind is favorable to the sea journey. Later, the wind fills the sails and helps sweep the ship away from the hermits' island.
It is a moonlit night when the bishop meets the three hermits on the island who will end up enlightening him. As he is rowing away from them, approaching his ship, "they could still be seen in the moonlight." But as the bishop boards the vessel, eventually "only the sea was to be seen, rippling in the moonlight." We know, indirectly, that it is dark outside, and that metaphorically, the bishop's spiritual understanding is still dark or lacking.
References to light come again as the hermits approach, walking on the water of the sea. From them, the bishop learns the meaning of the verse in the gospel of Matthew that says to pray not rotes prayers, but from the heart. This is the spiritual light of revelation, and it is contrasted to the natural or worldly light that has not given the bishop the insight he has needed:
A light shone until daybreak on the spot where they [the hermits] were lost to sight.