As it does in Luke, Matthew’s account the feeding of the 5,000 follows after Herod speculating that Jesus is John come back to life, but Matthew used this opportunity to tell the gruesome story of John’s death. Luke moved quickly from John’s death, to tell of the disciples’ successful mission, whereas Matthew tell us that when Jesus heard of John’s death he “withdrew to a deserted place”. Into this low point where we seem focused on the powerful political opposition that miracle comes as nice reminder that Jesus is God’s Messiah.
Perhaps it is this sombre context that caused Matthew to remember another miracle at this point, Jesus walks calmly up to the disciples, who are in a boat in a storm, and strolling across the water tells them not to be afraid! This provides us with clues/reminders that Jesus is not merely a human messiah/king, but indeed God incarnate. The elements are his servants, and like Yahweh in the Old Testament he tells his people they need not fear: “Take heart, it is I; do not be afraid.” (Mat 14:27) remember Abraham (Gen 15:1); Moses at the burning bush, Joshua and many others…
Then there’s the lovely detail of the enthusiastic Peter, first wanting a go, then remembering the storm, and finally saying “Lord, save me!” and as we’ll see the close of the story (remember endings are important and often signal, as beginnings also do often, what a story was about) stresses that Jesus is “son of God”.