Charles Ellicott Commentary Genesis 38:24

"And it came to pass about three months after, that it was told Judah, saying, Tamar thy daughter-in-law hath played the harlot; and moreover, behold, she is with child by whoredom. And Judah said, Bring her forth, and let her be burnt." — Genesis 38:24 (ASV)

Let her be burnt. — As, by law, the wife of Shelah, Tamar was condemned by Judah, by virtue 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.