Sophocles, "Ajax", trans. John Moore, in David Grene and Richmond Lattimore, eds., The Complete Greek Tragedies (1959), vol. 2, p. 250. There have been numerous translations of this play by Sophocles, with varying translations of these words, spoken by the character Tecmessa. The translation by George Young, The Dramas of Sophocles, p. 102 (1888) reads, "Men of perverse opinion do not know / The excellence of what is in their hands,/ Till some one dash it from them".https://en.wikiquote.org/wiki/Ignorance