Luke 2:45

And when they found him not, they turned back again to Jerusalem, seeking Him. Jesus having been seen by none of His kinsfolk on the way, His parents understood that He must have remained in Jerusalem; and so they sought Him there with great anxiety. Origen gives the reason, and Theophylact and Titus follow him. "But did they seek Him so anxiously? Did they imagine that the Child had been lost, or had wandered from the way?" Far otherwise, "For this would not have been characteristic of Mary's wisdom (she knew that Jesus was full of wisdom, yea, that He was God), and they could never have thought that the Child was lost, when they knew that He was Divine, but they sought Him lest by any means He might have gone away from them; lest perchance He had left them;" lest He should wish to remain not with them at Nazareth, but with others in Jerusalem, that He might there make haste to begin the ministry of teaching for which He had been sent by God. Origen adds, "They sought Him, lest perchance He might have gone away from them, lest He might have left them and betaken Himself elsewhere or as seems most probable lest He might have returned to heaven, to descend from thence when it should please Him... but she mourned because she was a mother, and the mother of a Son worthy of her immeasurable love because He had departed without her knowledge, and quite contrary to her expectation."