If you are not afraid to eat that which your mother body has deened as poisonous to your immortal soul, I would advise you to read the Last Testament of Judah to his children. This you will find in the 'Last Testament of the Patriarchs,' one of the books in the Psuedepigrapha of the Old Testament in English, by R. H. Charles. I'll just give you a short summerary here, which might be of some interest to you, for there you will find that Tamar was bethrothed to the sons (Plural) of Judah, in which sons, Judah had no delight.
Against his Father's wish, Judah (While full as a boot and drunk as a coot) took to wife a Canaanite woman by the name Bathshua, and she bore to Judah his three sons, Er, Onan and Shelah, none of whom succeeded Judah the ancestral father to the tribe of that name, which is descended from the two sons sired by Judah and born of Tamar: Parez, the successor to Judah, and Zerah the minor tribe of the scarlet thread, (Very, Very important). Judah chose Tamar as the wife for his son ER, and although I had said previously that she was the daughter of Levi, which no one picked up on, (It's hard to get a serious debate going in this forum) Tamar was in fact the daughter of a priest named Aram from Mesopotamia.
But Bashua did not want grand children by Tamar, as she was not a Canaanite and on the third night when Er had still not consumated the union, he was killed by an angel or so the story goes. Tamar was then given to Onan, but his mother Bathshua forbid that he sire a child to her, and after twelve months, when Judah found out, he commanded that his son Onan go into her, but he spilled his seed on the ground according to the command of his mother, and he died through wickness, and Judah wished to give Shelah to Tamar, but his mother did not permit it, because Tamar was not of the daughters of Canaan as she was. And while Judah was away, Bathshua went and took for Shelah a wife from Canaan; had not Judah sired the two sons to Tamah, he would have died childless, this he himself confesses to his descendants.