After the festival was over, while his parents were returning home, the boy Jesus stayed behind in Jerusalem, but they were unaware of it.
Thinking he was in their company, they traveled on for a day. Then they began looking for him among their relatives and friends.
When they did not find him, they went back to Jerusalem to look for him.
After three days they found him in the temple courts, sitting among the teachers, listening to them and asking them questions.
Everyone who heard him was amazed at his understanding and his answers.
When his parents saw him, they were astonished. His mother said to him, “Son, why have you treated us like this? Your father and I have been anxiously searching for you.”
“Why were you searching for me?”
“Didn’t you know I had to be in my Father’s house?”
Or "be about my Father’s business"
Scripture quoted by permission. Quotations designated (NIV) are from THE HOLY BIBLE: NEW INTERNATIONAL VERSION®. NIV®. Copyright © 1973, 1978, 1984, 2011 by Biblica. All rights reserved worldwide.