Genesis 38:24

Let her be burnt. — As being by law the wife of Shelah, Tamar was condemned by Judah in right of his position, as head of the family, to the punishment usual for adultery. In subsequent times, this penalty was limited to one who had married mother and daughter (Leviticus 20:14); or to the daughter of a priest guilty of unchastity (Leviticus 21:9). On this account, the Jewish expositors argue that Tamar belonged to a priestly family, and some even think that she was descended from Melchisedek.