cast pearls before swine, to

To offer something of value to those who cannot or will not appreciate it. The saying comes from Jesus’ teachings as recorded in the Gospel of St. Matthew (7:6): “Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet.” It was a well-known saying by Shakespeare’s time (“Pearl enough for a swine,” Love’s Labour’s Lost, 4.2) and a cliché long before Dickens wrote, “Oh, I do a thankless thing, and cast pearls before swine!” (Dombey and Son, 1848).