46 The traditional translation of “silver dross” (so , , ) never did make much sense because the parallel idea deals with hypocrisy—“fervent lips with an evil heart.” But silver dross would not be used over earthenware—instead it is discarded. Yet the clearly has “silver dross” (כֶּסֶף סִיגִים, kesef sigim). Ugaritic turned up a word spsg which means “glaze,” and this found a parallel in Hittite zapzaga[y]a. H. L. Ginsberg repointed the Hebrew text to k’sapsagim, “like glaze,” and this has been adopted by many commentators and recent English versions (e.g., , , , ). The final ם (mem) is then classified as enclitic. See, among others, K. L. Barker, “The Value of Ugaritic for Old Testament Studies,” 133 (1976): .
47 The word translated “fervent” actually means “burning, glowing”; the has “flattering lips” (as if from חָלַק [khalaq] rather than דָּלַק [dalaq]).
48 The analogy fits the second line very well. Glaze makes a vessel look beautiful and certainly different from the clay that it actually is. So is one who has evil intent (“heart”) but covers it with glowing speech.