From The Gospel of Matthew by Curtis Mitch and Edward Sri, commenting on Matthew 14:32-33:
It is important to realize how the disciples’ confession of Jesus as “Son of God” arises out of this story. They recognize that Jesus has done what Yahweh was said to do in the Jewish Scriptures. God is the one who treads upon the waves of the sea (Job 9:8; Hab 3:15) and who stills the storms that make the waters rough (Pss 65:8; 89:10; 107:28–30). Likewise, it is the Lord who reaches out and saves the faithful from drowning in seas of mortal danger (Pss 18:17; 144:7). Matthew does not cite these passages, but for those steeped in the Scriptures of Israel, the import of Jesus’ actions is evident. He is acting as only God can act, doing what only God can do.