Luke 2:41-52 (Revised Standard Version)

    41 Now his parents [Joseph and Mary] went to Jerusalem
          every year at the feast of the Passover.
    42 And when he [Jesus] was twelve years old, they went up
          according to custom;
    43 and when the feast was ended, as they were returning,
          the boy Jesus stayed behind in Jerusalem. His parents did
          not know it,
    44 but supposing him to be in the company they went a day's
          journey, and they sought him among their
          kinsfolk and acquaintances;
    45 and when they did not find him, they returned to
          Jerusalem, seeking him.
    46 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.
    48 And when they saw him they were astonished; and his mother said
          to him, "Son, why have you treated us so? Behold, your father
          and I have been looking for you anxiously."
    49 And he said to them, "How is it that you sought me? Did you not
          know that I must be in my Father's house?"
    50 And they did not understand the saying which he spoke to them.
    51 And he went down with them and came to Nazareth,
          and was obedient to them; and his mother
          kept all these things in her heart.