Luke 2:44 - Coke's Commentary on the Holy Bible

Supposing him to have been in the company— Several families then travelled together, as they do at present on such occasions, in companies, or caravans, as they are called in the East. In these companies it was not unusual for persons to leave their own families, and mix with others, for the sake of conversation in the day-time; but at night they always joined their own families again. The parents of Jesus therefore supposing him to have been among their relations, were not solicitous about him in the day; but not finding him at night, they became anxious on account of his absence; and thus having spent one day on their journey, they reached Jerusalem on the second, and spent the third in searching after him there. See on Luke 2:49. Grotius, and Shaw's Travels, Preface, p. 9.