The Heavens Open over the Beloved Son
Jesus is baptized among the people, but Luke immediately distinguishes him from the crowd: as he prays, heaven opens, the Holy Ghost descends bodily like a dove, and the Father identifies him as the beloved Son. Luke has already used Spirit language throughout the infancy narrative; here the Spirit rests publicly upon Jesus at the threshold of his ministry.
Where this fits in the story: “Son” language gathers several biblical trajectories at once—royal sonship, Israel as God’s son, the beloved-son pattern, and the Adamic horizon Luke will make explicit in the genealogy that follows. The scene should not be reduced to only one Old Testament background.