Girl with a Pearl Earring, Vermeer
c. 1665-1666; Oil on canvas, 44.5 x 39 cm; Royal Cabinet of Paintings Mauritshuis, The Hague
"At all times women have been wont to wear pearls at their ears. Pliny assigns as a reason the pleasure that they take in their jingle one against the other. But I, when I remember how God's chosen servant Isaac sent earrings as the first pledge of his love to Rebecca, am inclined to believe rather that the mystical signification is that the first tribute of a husband, and that which a wife should watchfully preserve for him, is her ear, that no sound or language may enter therein, but the sweet music of pure and modest words, which are the pearls of great price of the Gospel; one should always remember that poison enters the soul by the ears, as it enters the body by the mouth."
St Francis de Sales, Introduction to the Devout Life, pg 230.