This chapter seems at first out of place since it interrupts the story of Joseph, but remember that this is the toledotof Jacob. This is the story of what happened to his whole family, not just Joseph. The central problem with which the chapter deals is childlessness. The events of the chapter must span at least 20 years, years during which Joseph was lost to his family (cf. 37:2; 41:46-47; 45:6).
Judah tried unsuccessfully to insure the levirite rights of his daughter-in-law Tamar. As a last resort Tamar deceived him into having sexual intercourse with her by masquerading as a prostitute. She thereby maintained her right to become the mother of Judah's children, the younger of which displaced his older twin in an unusual birth.
"The following sketch from the life of Judah is intended to point out the origin of the three leading families of the future princely tribe in Israel [Shelah, Perez, and Zerah] and at the same time to show in what danger the sons of Jacob would have been of forgetting the sacred vocation of their race, through marriages with Canaanitish women, and of perishing in the sin of Canaan, if the mercy of God had not interposed, and by leading Joseph into Egypt prepared the way for the removal of the whole house of Jacob into that land, and thus protected the family, just as it was expanding into a nation, from the corrupting influence of the manners and customs of Canaan."817
This chapter records the compromise of the Israelites, specifically Judah, with the Canaanites, Shua and Tamar, that resulted in the confusion of seed, the chosen with the condemned. Jacob alluded to this mixture in his prophecy (ch. 49). It is perhaps the basis for the prohibition against mixing various kinds of seed, yoking two different kinds of animals together, weaving two kinds of thread into cloth, etc., in the Mosaic Law.818
"One gets the distinct impression that ever since the Dinah incident (ch. 34) Jacob has less and less control over the behavior of his family."819
38:1-11 Levirite marriage (the marriage of a man to his deceased brother's wife to provide his brother with an heir) was a common custom in the ancient Near East at this time (vv. 8-10).820It was common also in Asia, Africa, and other areas, but it evidently originated in Mesopotamia. The Mosaic Law did not abolish it but restricted it in Israel to preserve the sanctity of marriage (cf. Deut. 25:5-10).
"The enormity of Onan's sin is in its studied outrage against the family, against his brother's widow and against his own body. The standard English versions fail to make clear that this was his persistent practice. When(9) should be translated whenever.'"821
Onan's refusal to give Tamar a child not only demonstrated a lack of love for his deceased brother. It also revealed Onan's selfish heart that wanted for himself what would have gone to his elder brother's heir. If Tamar had born him a son, that child would have been the perpetuator of Er's name as well as that of Onan (cf. Ruth 4:5, 21-22). God judged Onan's sin severely because descendants were important in His plans for the patriarchs. Onan was deliberately frustrating the fulfillment of God's promises to Abraham, Isaac, and Jacob (cf. 11:4).
Judah sinned against Tamar by forcing her to live as a widow (v. 11). He wrongly blamed Tamar for the death of his sons (cf. v. 26) rather than blaming his sons. Tamar had every right to children. Moreover as a member of the chosen family, Judah should have made certain that she had another legitimate opportunity to bear children.
Judah comes across at the beginning of this incident again as a hard and callous man. He had previously suggested selling Joseph into slavery to make money from him and deceiving Jacob despite Reuben's protests (37:26-27, 29-30). Now he showed no grief over the deaths of his sons, in contrast to Jacob who mourned inconsolably over Joseph's apparent death (37:34-35). Judah also ordered the burning of his daughter-in-law (38:24).
38:12-30 When Judah deceived Jacob, a goat and an item of clothing featured in the trick, and here a goat and an item of clothing again figure in Tamar's deception of Judah. Tamar's strategy for obtaining her right was not commendable, but the fact that she sought to obtain seed by Judah shows her legitimate desire for children at least. It may also reveal her desire to enter into the Abrahamic promises by bearing children for Judah and his sons. Jacob's family experienced deception again.
"Tamar qualifies as a heroine in the story, for she risked everything for her right to be the mother in the family of Judah and to protect the family."822
"Although Tamar's actions in this regard may seem strange to us, there is evidence that among ancient Assyrian and Hittite peoples, part of the custom was that the levirite responsibility could pass to the father of the widow's husband if there were no brothers to fulfill it. Thus Tamar was only trying to acquire that to which she had a legal right."823
Moses did not identify her motivation. Whether or not she understood and believed the promises to the patriarchs regarding their sacred vocation she did become an ancestor of the Messiah (Ruth 4:18; Matt. 1:3).
"Just as in chapter 20 where the seed of Abraham was protected by the righteous' (saddiq, 20:4; NIV, innocent') Abimelech (cf. also 26:9-11), it is the woman Tamar, not Judah the patriarch, who is ultimately responsible for the survival of the descendants of the house of Judah."824
Judah's response to his sins against God and Tamar seems to have been genuine repentance (v. 26). He confessed his wrong and repented by ceasing from further sexual relations with her, his daughter-in-law. It is evidently because his repentance was genuine that Jacob did not exclude him from receiving a special blessing as he did Reuben, Simeon, and Levi. Because he humbled himself God raised him to be the chief of the house of Israel and blessed the children that he fathered even though they were a result of his sin. (Compare God'sblessing of Solomon even though he was the fruit of the unlawful union of David and Bathsheba.)
". . . in its biographical sketches, character change is what Genesis is all about: Abram becomes Abraham; Jacob becomes Israel. Particularly in Jacob's family we see examples of character change: Reuben, violator of his father's concubine, later shows great concern for both Joseph and his father, while the upstart cocky Joseph becomes the wise statesman who forgives his brothers. Thus, this chapter has a most important role in clarifying the course of the subsequent narrative; without it we should find its development inexplicable."825
Perez (meaning a breach or one who breaks through) was the first of the twins born (vv. 27-30). He became the ancestor of David and Messiah (Matt. 1:3). Moses may have included the unusual circumstances surrounding the birth of these twins in the record to emphasize God's selection of the son through whom the line of blessing would descend.
"He [Judah] and his brothers sold their younger brother into Egypt, thinking they could thwart God's design that the elder brothers would serve the younger Joseph. Yet in Judah's own family, despite his attempts to hinder Tamar's marriage, God's will worked out in a poignant confirmation of the principle that the elder would serve the younger."826
The scarlet thread marked the second-born, Zerah (dawning, i.e., red or scarlet). It did not indicate the Messianic line. That line came through the other son, Perez. The thread is perhaps just a detail of the story that explains the names given.
"As the Jacob narrative began with an account of the struggle of the twins Jacob and Esau (25:22), so now the conclusion of the Jacob narrative is marked by a similar struggle of twins. In both cases the struggle resulted in a reversal of the right of the firstborn and the right of the blessing. . . . The brevity and austerity with which the narrative is recounted leaves the impression that the meaning of the passage is self-evident to the reader. Indeed, coming as it does on the heels of a long series of reversals in which the younger gains the upper hand on the elder, its sense is transparent."827
Judah's hedonistic willfulness in this chapter contrasts with Joseph's self-control in sexual temptation in the next.
God corrects those who disregard His plan and pursue lives of self-gratification often using talionic justice (i.e., reaping the same kind of punishment as the sin that we sow) in His discipline.