Matthew 14:25

The Jews, like the Romans, divided night-time into four "watches," or four shifts for people to stand guard. The fourth watch, then, ended at daybreak. What we see, then, is morning, representing the dawning of a new church.

And then the extraordinary vision, of Jesus walking on the water. This represents the fact that in this new church the Lord's goodness would bring life to even those holding the disconnected external ideas represented by the sea.