Jesus: The Beloved King and Davidic Heir

At the Jordan, three things happen at once: a prophetic act, the Spirit descending, and a voice from heaven. All three designation markers are present simultaneously. This is an accession.
The voice itself is a composite quotation. You are my son comes from Psalm 2:7 - a psalm read at the succession to the throne of a new Davidic king. With you I am well pleased echoes Isaiah 42:1, the servant. The beloved language reaches back toward Genesis 22.
So the baptism is not the start of a career. It is a coronation, announced in the vocabulary of Israel's kingship.
Scripture links:
- Matthew 3:17 - this is my beloved Son, with whom I am well pleased.
- Psalm 2:7 - you are my Son, today I have begotten you.
A king was anointed, declared and acknowledged. All three happened in a river.