Psalm 23: The Good Shepherd Jesus Christ

Verse 1: The Lord is my shepherd; I shall not want.

Psalm 23 is a song of praise from a sheep. This sheep highly exalts its shepherd. David, who became a sheep, knows the shepherd well. The list of the sheep's praises is because it was his job to tend the sheep. However, David could not declare himself as the good shepherd. 

Finally, in the Gospel of John, Jesus himself declared that he is the good shepherd. Or, the Johannine community comprehensively felt, understood, and confessed Jesus as the good shepherd. This is a declaration of revelation, the word that opens the heavens. Jesus will perform his shepherd duties well, just as he declared (his name). It is because Jesus is a descendant of David.