Luke 2:43-51 ESV
And when the feast was ended, as they were returning, the boy Jesus stayed behind in Jerusalem. His parents did not know it, but supposing him to be in the group they went a day’s journey, but then they began to search for him among their relatives and acquaintances, and when they did not find him, they returned to Jerusalem, searching for him. After three days they found him in the temple, sitting among the teachers, listening to them and asking them questions. And all who heard him were amazed at his understanding and his answers. And when his parents 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 searching for you in great distress.” And he said to them, “Why were you looking for me? Did you not know that I must be in my Father’s house?” And they did not understand the saying that he spoke to them. And he went down with them and came to Nazareth and was submissive to them. And his mother treasured up all these things in her heart.
ESV: English Standard Version 2016