On the water: In Matthew’s previous water-miracle (8:23-27), Jesus was portrayed as the God of the Old Testament who calmed the chaotic waters. Matthew now pictures Jesus with the power to walk on the chaotic waters. This scene echoes Ps 77:20, where it is said of God, “Through the sea was your way, and your path through the deep waters, though your footsteps were not seen.”
An allegory of the Church is established here. The disciples in the boat represent Matthew’s community, which is threatened by evil (the fourth watch of the night) and the turmoil (tossed about by the waves) of the times (persecution?). However, when the Church is in need and all seems lost, Jesus is there. Peter, the first leader of the Church, addresses Jesus as “Lord,” and he momentarily walks on the water like his master. His cry, “Lord, save me!” is the same as that of the cry of the Church. Like God in the Old Testament, Jesus stretches out his hand and saves Peter.