Luke 2:41-51
Chapter 2
And when Jesus was twelve years old, he went up with them according to the custom of this feast.
After the festival ended, they left, but the boy Jesus stayed in Jerusalem, and his parents didn’t know it.
They assumed he was with their group of travelers, and after walking all day, they searched for him among their relatives and friends.
As they didn’t find him, they returned to Jerusalem to look for him;2
and on the third day, they found him in the temple, sitting among the teachers, listening to them and asking questions.
All the people were amazed at his understanding and his answers.
His parents were very surprised when they saw him, and his mother said to him:
“Son, why have you done this to us? Your father and I were very worried while searching for you.”
Then he said to them:
“Why were you looking for me? Did you not know that I must be in my Father’s house?”
But they did not understand this answer.
Jesus went down with them to Nazareth and remained obedient to them. His mother kept all these things in her heart.

Commentaries
The Child Jesus in the Temple.
With this account, Luke reveals two key truths about Jesus’ self-awareness: his divine sonship (Jesus’ first words in Luke’s Gospel are “my Father”) and his mission (“my Father’s business”). No one understands anything, no one discusses anything, not even his own parents; however, Mary kept all these things in her heart.