Most surviving altarpieces of this scale and ambition were built for churches: raised on public altars, seen by whole congregations, paid for by guilds or bishops. This one was not. Its scale, barely two feet wide when opened, and its two donor portraits kneeling in the left wing identify it instead as a private commission, made for the wall of an ordinary well off household in the southern Netherlands sometime around 1427 to 1432.
That distinction changes what the painting is doing. A church altarpiece has to hold a crowd's attention from a distance and survive weekly repetition. A domestic devotional panel like this one rewards a single person standing close, returning to it daily, noticing something new each time, exactly the kind of looking that eventually turns up two small mousetraps on a carpenter's bench. The Virgin's private domestic interior in the central panel, down to the folded towel and the kettle on the fire, was painted for viewers who lived in rooms very much like it themselves.
The Metropolitan Museum of Art has held the triptych since 1956, acquired for The Cloisters, its medieval branch built specifically to give paintings like this one a setting closer to the intimate devotional space they were made for than a conventional museum gallery could offer.