Luke 2:42-45

And when he was twelve years old, they went up, as their way was, to the feast; And when the days of the feast came to an end and they were going back, the boy Jesus was still in Jerusalem, but they had no knowledge of it: And in the belief that he was with some of their number, they went a day's journey; and after looking for him among their relations and friends, And seeing that he was not there, they went back to Jerusalem, to make search for him.