Luke 2.46-47: After three days they found him in the temple, sitting among the teachers, listening to them and asking them questions. (47) And all who heard him were amazed at his understanding and his answers. (ESV)
Verse 41 of chapter 2 tells us that Jesus and his family travelled every year to Jerusalem at the time of the feast of the Passover. When Jesus was 12 years old his family attended the Passover and began the trip back home, presuming Jesus was with them. When the group could not find Jesus they returned to Jerusalem, and after a three day search they found him in the temple with the teachers. This would be similar to a twelve year old child participating in a serious discussion with the faculty of a prestigious university.
And Jesus at age twelve demonstrated to these highly regarded teachers his insight and understanding. Verse 46 says that Jesus asked them questions, but the source of their amazement of him was because of his understanding and his answers to their questions. So the wisdom and favor of God working in Jesus during the whole of his childhood referred to in verse 40 of chapter 2 are revealed before the leading scholars of that time in Israel.
Luke does not tell us the subject matter of the questions and answers, but it is highly likely that some portion of it covered topics related to the law. And during the early part of Jesus’ public ministry, set forth in the Sermon on the Mount recorded in the Gospel of Matthew, chapters 5 through 7, Jesus will demonstrate his wisdom and favor and insight from God, because he will teach the distinction between the legalistic interpretation of the law, and the genuine application of the law from God’s perspective.