Malachi 3:2 , Hebrew, borith, the cleanser; in Jeremiah 2:22 distinguished from nitre, which see. It is well known that the ancient used certain vegetables and their ashes for the purpose of cleansing linen, etc. The ashes of seashore plants contain carbonate of potash. Combined with oil or fat the alkalies produced soap; but it is not known in what forms the Jews used them.