Now his parents went to Jerusalem every year at the feast of the
passover. And when he was twelve years old, they went up to Jerusalem
after the custom of the feast. And when they had fulfilled the days, as
they returned, the child Jesus tarried behind in Jerusalem; and Joseph
and his mother knew not of it. But they, supposing him to have been in
the company, went a day's journey; and they sought him among their
kinsfolk and acquaintance. And when they found him not, they turned back
again to Jerusalem, seeking him And it came to pass, that after three
days they found him in the temple, sitting in the midst of the doctors,
both hearing them, and asking them questions. And all that heard him were
astonished at his understanding and answers. And when they saw him, they
were amazed: and his mother said unto him: "Son, why hast thou thus dealt
with us? behold, thy father and I have sought thee sorrowing". And he
said unto them: "How is it that ye sought me? wist ye not that I must be
about my Father's business?" And they understood not the saying which he
spake unto them. And he went down with them, and came to Nazareth, and
was subject unto them: but his mother kept all these sayings in her
heart. (Luke 2, 41-51)