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.
And when they had fulfilled the days (the seven days of the festival); as they returned. Yes, they had to return. For if the duties of life must give place to worship, worship in its turn must give place to them. Jerusalem is good; but Nazareth is good too. Let him then who neglects the one, on pretext of attending to the other, ponder this scene. Work and Worship serve to relieve each other, and beautifully alternate.
The child Jesus tarried behind in Jerusalem; and Joseph and his mother knew not of it. Accustomed to the discretion and obedience of the lad, as Olshausen says, they might be thrown off their guard.