God does not break his promises. He chose David, an overlooked shepherd boy to rule his people and through him, he brought Jesus.
Jesus is the true David so to speak.
God bestowed strength on him to endure the cross.
God anointed Jesus as the Messiah, the anointed saviour.
God appointed Jesus and sustained him always.
The enemy never won with Jesus, he was defeated.
God’s faithfulness love and strength were poured in Jesus.
Jesus is the firstborn of many brothers.
The covenant made between God and Jesus and us will never be broken.
Jesus throne will last forever. ( see verses 19-29)
What makes these promises even more wonderful is that if we are in Christ, those promises are true for us too.