Judah was to inherit the Abrahamic blessing of leadership or the family’s authority. Reuben lost that blessing by rebelling against his father, when he went into and lay with Bilhah one of Jacob’s wives, a concubine, but, nevertheless, his wife. By doing so, he insured that no other child would come from Rachel, for being Rachel’s handmaid, Bilhah’s children were legally considered children born to Rachel, whom Reuben considered Leah’s, his mother’s, rival. The text doesn’t tell us what, if anything, Jacob said or did at that time, but it does tell us that Jacob knew what Reuben had done (Genesis 35:22). Therefore, Reuben lost his blessing as Jacob’s firstborn (Genesis 49:3-4).
Next in line would have been Simeon and Levi, but they proved their contempt for their father and the family, as a ‘covenant keeping’ family, when they broke covenant with the men of Shechem and slew every male in their city. Therefore, the family leadership and authority fell to Judah, Leah’s fourth son, because her first three sons proved themselves unworthy of the blessing. It is in this context, then, that we should understand the content of Genesi 34. Something needed to be said about the man, who would inherit the blessing of family’s leadership, because, once the blessing was given, it would be through Judah’s lineage, the Messiah would come.
We aren’t given the circumstances, but it appears that Judah separated himself from his brethren before he married. Although he worked with his brothers, he dwelt apart from them in the village of Adullam, in Canaan. It seems that Hirah, a citizen of that village, kept a lodging house, and Judah dwelt there. During this time, Judah met the daughter of a certain Canaanite named Shuah. Judah was pleased with her and went in onto her, meaning he took her for his wife (Genesis 38:1-2, cp. 38:12). Whether or not the union, itself, was improper, which is the conclusion of some scholars, because she was a Canaanite woman, the text itself doesn’t say. Yet, one needs to ask, from where would the sons of Jacob take their wives? Joseph took an Egyptian for his wife, and that seemed acceptable. Moreover, much later Moses married a Cushite woman, and when Miriam and Aaron took exception to this (Numbers 12:1), the Lord corrected them. Therefore, if the woman, which a male descendant of Jacob married, was pleased to dwell under the customs of Abraham, it doesn’t appear that the marriage was objectionable, despite the woman’s heritage.
Judah’s wife conceived and bore him three sons: Er (verse-3), Onan (verse-4) and Shelah (verse-5), and the youngest was born in Chezib, which is Achzib in Canaan, implying Er and Onan were born in Adullam. Due to Judah’s later lie to his daughter-in-law, Tamar, Chezib (Achzib), the village where Judah’s son, Shelah, was born, became associated with lying (cp. Micah 1:14). There the prophet used a play on words. Achzib (H392), which is the city shall be Achzab (H391), meaning a ‘lie’ (Genesis 38:5).
When Er came of age, Judah acquired a wife for him, and her name was Tamar. However, Er was a wicked man, so the Lord slew him, before he had any children (Genesis 38:6-7). The Levirate custom was in force prior to the Mosaic Law, which incorporates its use for males who marry but die without leaving a descendant (Deuteronomy 25:5-10). It was this custom that Judah had in mind, when he had his second son, Onan, marry his brother’s widow, Tamar. The firstborn of their union would have been Er’s descendant, according to the law of descendancy. However, although he married Tamar, Onan apparently hated his brother and refused to sire any children for Er. This displeased the Lord, so he slew Onan also (Genesis 38:8-10).
Apparently, these events happened rather quickly, and Shelah, Judah’s last remaining son, wasn’t considered old enough to marry. Nevertheless, this was probably a matter of Judah’s interpretation. In other words, it was a decision of convenience, which Judah made, so he could save face by refusing to give his son, Shelah, to Tamar. By this time, perhaps, Judah considered Tamar cursed, for both his elder sons died after marrying her (Genesis 38:11). Either Judah thought he had made a mistake by choosing a Canaanite woman to marry Er, or Judah was superstitious, which may be closer to the truth, if he was living among the Canaanites, as seems to be the case.
The work of the Lord was still not taken into account among most of the sons of Jacob. Only Joseph seems to have had a healthy relationship with the Lord. None of the other sons of Jacob stand out, as following their father’s manner of worshiping the Lord God Almighty. Therefore, for all intents and purposes, even though they offer Jacob some respect as the patriarch of the family, they have abandoned his manner of living and adopted the characteristics of the surrounding Canaanite communities.