John Calvin Commentary Luke 2:33

"And his father and his mother were marvelling at the things which were spoken concerning him;" — Luke 2:33 (ASV)

And his father and mother were wondering Luke does not say that they were astonished at it as a new thing, but that they contemplated with reverence, and embraced with fitting admiration, this prediction of the Spirit spoken by Simeon, so that they continued to make progress in the knowledge of Christ. We learn from this example that, once we have come to possess a right faith, we ought to gather from every side whatever may help to give it additional strength. The person who has achieved great proficiency in the word of God does not fail to admire whatever they read or hear every day that contributes to their unceasing progress in faith.