Luke 2:41-47. “And his parents went every year to Jerusalem, at the solemn day of the pasch. And when he was twelve years old, they going up into Jerusalem, according to the custom of the feast, and having fulfilled the days, when they returned, the child Jesus remained in Jerusalem; and his parents knew it not… And it came to pass, that, after three days, they found him in the temple, sitting in the midst of the doctors, hearing them, and asking them questions. And all that heard him were astonished at his wisdom and his answers.”
“The finding of Jesus in the temple is the only event that breaks the silence of the Gospels about the hidden years of Jesus. (Cf. Lk 2:41-52) Here Jesus lets us catch a glimpse of the mystery of his total consecration to a mission that flows from his divine sonship: ‘Did you not know that I must be about my Father’s work?’ (Lk 2:49)” (CCC, 534). Vatican
Our Father, 10 Hail Marys (contemplating the mystery), Glory Be and Fatima Prayer.