Contradiction with Exodus 20:14
This verse forbids adultery, while Genesis 38:12 involves behaviors that can be seen as leading to adultery within the broader narrative of Genesis 38.
Exodus 20:14: Thou shalt not commit adultery.
Contradiction with Leviticus 18:16
This verse prohibits lying with your brother’s wife, yet Judah, in the broader context of Genesis 38, goes in unto his daughter-in-law, Tamar.
Leviticus 18:16: Thou shalt not uncover the nakedness of thy brother's wife: it [is] thy brother's nakedness.
Contradiction with Deuteronomy 25:5-6
This levirate marriage law requires a brother to marry his deceased brother’s widow to raise offspring, which stands in contrast to Judah’s actions in Genesis 38:12.
Deuteronomy 25:5-6: If brethren dwell together, and one of them die, and have no child, the wife of the dead shall not marry without unto a stranger: her husband's brother shall go in unto her, and take her to him to wife, and perform the duty of an husband's brother unto her. [her husband's...: or, her next kinsman]
Contradiction with 1 Corinthians 6:18
This verse advises to flee fornication, contrasting with Judah’s actions after his wife’s death in Genesis 38:12, which lead to fornication.
1 Corinthians 6:18: Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.
Contradiction with James 1:14-15
This verse describes the progression from lust to sin to death, contradicting the narrative of Judah’s temptation and actions outlined in Genesis 38.
James 1:14-15: But every man is tempted, when he is drawn away of his own lust, and enticed.