Tobit and Anna were the parents of Tobias who saved his father's sight with the help of the Archangel Raphael. Tobit had been reduced to poverty by God as a test: Anna supported them with her spinning wheel. Book of Tobit (2: 11 and 4: 21). If the identification of the subject as Tobit and Anna is correct, the spinning-wheel is presumably a reference to Anna working for money and the bare cupboard an allusion to their poverty. Because of the interior setting the painting was for a long time been interpreted as being a genre scene with an old couple. However, the subject was identified by comparison with a similar painting by Rembrandt ('Anna and the Blind Tobit'), also in the National Gallery's Collection.
In 17th-century Holland, paintings were sometimes protected by curtains, and illusionistic representations of them, as in the curtain set in front of the scene on the right, are not uncommon.