"the descendant of Heth" or "a descendant of Heth." The Hittite people were the descendants of Heth. (See: [[rc://en/ta/man/translate/translate-names]])
Here "they" refers to Judith and Basemath. To make someone sorrowful or miserable is spoken of as if "sorrow" were an object that a person could bring to another person. AT: "They made Isaac and Rebekah sorrowful" or "Isaac and Rebekah were miserable because of them" (See: [[rc://en/ta/man/translate/figs-metaphor]])