Isaiah repeatedly speaks of the LORD revealing salvation to the nations and bringing consolation to Israel.
Simeon does not merely predict that Jesus will someday announce salvation; holding Jesus, he says he has seen God's salvation.
The statement is metaphorical and salvation remains God's work, but Luke's identification of the child with God's saving action is strongly Christological.
Simeon blesses God and prophetically describes Jesus' future significance.
The Spirit-led testimony presents Jesus as the decisive embodiment of God's promised saving work.